Biography

Hi! My name is Leyi Pan (潘乐怡). I am currently a 2nd-year Ph.D. student at the School of Software, Tsinghua University, advised by Prof. Lijie Wen. Before that, I received my B.Eng. from Tsinghua University in 2024.

I am currently a research intern on LLM reasoning and reinforcement learning at Tongyi Lab, Alibaba Group (mentored by Dr. Yunpeng Zhai). Previously, I interned at Zhipu AI and served as a research assistant at CUHK MISC Lab.

My research interests mainly lie in:

• LLM Reinforcement Learning (current focus)
• Trustworthy AI

Feel free to reach out if you would like to discuss research or explore potential collaboration!

News

• 2026.06 Our new work RLCSD is released on arXiv.
• 2026.06 MarkLLM has reached 1k stars!
• 2026.05 MarkDiffusion receives minor revision at JMLR.
• 2026.04 d-TreeRPO is accepted by ACL 2026 Main!
• 2025.08 Omni-SafetyBench is released on arXiv.
• 2025.07 GLM-4.5V and GLM-4.1V-Thinking is released on arXiv! (76 authors including Leyi Pan)
• 2025.05 Can LLM Watermarks Robustly Prevent Unauthorized Knowledge Distillation? is accepted by ACL 2025 Main.

Selected Preprints / Publications

A full publication list is available on my Google Scholar page. (* denotes equal contribution)

LLM Reinforcement Learning (current focus)

• RLCSD: Reinforcement Learning with Contrastive On-Policy Self-Distillation
  Leyi Pan, Yunpeng Zhai, Zheyu Fu, Shuchang Tao, Bolin Ding, Aiwei Liu, Lijie Wen, Jingren Zhou.
  Preprint, 2026 | PDF | Code
• d-TreeRPO: Towards More Reliable Policy Optimization for Diffusion Language Models
  Leyi Pan, Shuchang Tao, Yunpeng Zhai, Zheyu Fu, Liancheng Fang, Minghua He, Lingzhe Zhang, Zhaoyang Liu, Bolin Ding, Aiwei Liu, Lijie Wen.
  ACL Main, 2026 · CCF-A | PDF | Code
• GLM-4.5V and GLM-4.1V-Thinking: Towards Versatile Multimodal Reasoning with Scalable Reinforcement Learning
  Zhipu AI (76 authors including Leyi Pan).
  Technical Report, 2025 | PDF | Code

Trustworthy AI

• Omni-SafetyBench: A Benchmark for Safety Evaluation of Audio-Visual Large Language Models
  Leyi Pan, Zheyu Fu, Yunpeng Zhai, Shuchang Tao, Sheng Guan, Shiyu Huang, Lingzhe Zhang, Zhaoyang Liu, Bolin Ding, Felix Henry, Aiwei Liu, Lijie Wen.
  Under Review (ACM MM, CCF-A, score: 44442, max: 5) | PDF | Code
• MarkDiffusion: An Open-Source Toolkit for Generative Watermarking of Latent Diffusion Models
  Leyi Pan, Sheng Guan, Zheyu Fu, Luyang Si, Huan Wang, Zian Wang, Hanqian Li, Xuming Hu, Irwin King, Philip S. Yu, Aiwei Liu, Lijie Wen.
  Under Review (JMLR Minor Revision, CCF-A) | PDF | Code
• Can LLM Watermarks Robustly Prevent Unauthorized Knowledge Distillation?
  Leyi Pan, Aiwei Liu, Shiyu Huang, Yijian Lu, Xuming Hu, Lijie Wen, Irwin King, Philip S. Yu.
  ACL Main, 2025 · CCF-A | PDF | Code
• WaterSeeker: Pioneering Efficient Detection of Watermarked Segments in Large Documents
  Leyi Pan, Aiwei Liu, Yijian Lu, Zitian Gao, Yichen Di, Lijie Wen, Irwin King, Philip S. Yu.
  NAACL Findings, 2025 | PDF | Code
• MarkLLM: An Open-Source Toolkit for LLM Watermarking
  Leyi Pan, Aiwei Liu, Zhiwei He, Zitian Gao, Xuandong Zhao, Yijian Lu, Binglin Zhou, Shuliang Liu, Xuming Hu, Lijie Wen, Irwin King, Philip S. Yu.
  EMNLP Demo, 2024 | PDF | Code
• A Survey of Text Watermarking in the Era of Large Language Models
  Aiwei Liu*, Leyi Pan*, Yijian Lu, Jingjing Li, Xuming Hu, Lijie Wen, Irwin King, Philip S. Yu.
  ACM Computing Surveys | PDF
• A Semantic Invariant Robust Watermark for Large Language Models
  Aiwei Liu, Leyi Pan, Xuming Hu, Shiao Meng, Lijie Wen.
  ICLR, 2024 · CCF-A | PDF | Code
• An Unforgeable Publicly Verifiable Watermark for Large Language Models
  Aiwei Liu, Leyi Pan, Xuming Hu, Shuang Li, Lijie Wen, Irwin King, Philip S. Yu.
  ICLR, 2024 · CCF-A | PDF | Code

Projects

I enjoy building useful and reusable research frameworks for the community.

MarkLLM

An open-source toolkit for LLM watermarking, covering watermark generation, detection, evaluation, visualization, and extensible algorithm implementations.

Paper | Code

MarkDiffusion

An open-source toolkit for generative watermarking of latent diffusion models, designed for reproducible evaluation and easy integration of watermarking methods.

Paper | Code

Education

• 
  2024.09 - Present, Ph.D. @ Tsinghua University, Beijing, China.
• 
  2020.09 - 2024.06, B.E. @ Tsinghua University, Beijing, China.

Internships

• 2025.07 - PresentTongyi Lab, Alibaba Group, Research Intern
• Topic: LLM reasoning and reinforcement learning. Mentor: Yunpeng Zhai.
• 2024.10 - 2025.06AI Lab, Zhipu AI, Research Intern
• Topic: Reasoning and reinforcement learning for multimodal large language models. Mentor: Shiyu Huang.
• 2024.06 - 2024.08CUHK MISC Lab, Research Assistant
• Topic: Trustworthy AI. Supervisor: Irwin King.
• 2023.06 - 2023.08KuaiShou Technology, Research Intern
• Topic: Tool-integrated agent. Mentors: Haojie Pan, Ruiji Fu.

Service

• Reviewer: ACL ARR, NeurIPS, ICLR.

Honors and Awards

• 2025   Tsinghua Excellent First-class Scholarship / 清华大学综合优秀一等奖学金.
• 2024   Outstanding Graduate of Beijing / 北京市优秀毕业生.
• 2024   Outstanding Graduate of Tsinghua / 清华大学优良毕业生.
• 2024   Tsinghua Outstanding Graduation Project / 清华大学优秀毕业设计.
• 2021-2023   Tsinghua Excellent Student Award / 清华大学综合优秀奖学金.

Contact

• Email: panly24@mails.tsinghua.edu.cn
• Email: panleyi2003@gmail.com