An anonymous network scanning system was proposed for traceability problem faced by network scanning tools during scanning. Firstly, the anonymous system was combined with the network scanning tool to implement anonymous scanning. Then, the local privatization of the system was implemented based on existing anonymous system. Thirdly, through traffic analysis, it was found that Nmap's multi-process scanning would become a single-process scan due to proxy chain, resulting in lower scan scan performance. Finally, a performance optimization scheme based on multi-Namp process concurrency was proposed, which divided the overall scan task into multiple scan tasks and assigned them to multiple separate Nmap processes in parallel. The experimental results show that the scanning delay of the performance optimization scheme is close to that of the normal scanning system, and achieves the purpose of improving the performance of the anonymous scanning system. Therefore, the optimized network anonymous scanning system hinders the traceability and improves the scanning efficiency.