Abstract: Objective After years of operation, Shanghai Rail Transit Line 6 signaling system faces equipment aging and frequent failures. To enhance this system reliability, adaptability, and operational efficiency, it is imperative to develop an overhaul plan for the signaling system of Shanghai Rail Transit Line 6. Method Based on an analysis of current signaling system status and operational performance, three solutions are proposed: functional restoration of the CBTC（communication-based train control） system through equipment renewal（option 1）; implementation of a new TACS（train autonomous circumnavigation system） plan（option 2）; comprehensive upgrade of the CBTC system based on DTO（driverless train operation with attendant） mode（option 3）. The signaling system architecture and primary challenges for each option are examined. After comprehensive comparison, option 3 is identified as optimal. Using simulation analysis verification method, based on the actual line upgrading conditions, the travel speed, journey time, mainline tracking interval, and dwell time before and after upgrade are analyzed and compared. Result ＆ Conclusion Option 3 effectively shortens train tracking intervals, extends dwell time, and significantly enhances operational safety and service quality on Shanghai Rail Transit Line 6, improving both the reliability and operational efficiency of signaling system.