This article introduces PaperOrchestra, a multi-agent system that transforms raw idea summaries and experimental logs into submission-ready AI research papers using agents for outlining, plotting, literature review, writing, and refinement. It outperforms single-agent and state-of-the-art baselines on PaperWritingBench, a new benchmark of 200 CVPR and ICLR papers, in both literature review and overall manuscript quality.