The invention provides a CBTC (Communications Based Train Control) signal system simulation testing platform, which comprises a signal bus, a simulation vehicle-mounted and simulation vehicle system, a simulation station, a simulation rail side system, a three-dimensional vision system and a testing platform management system, wherein the simulation vehicle-mounted and simulation vehicle system, the simulation station, the simulation rail side system, the three-dimensional vision system and the testing platform management system are mutually connected through the signal bus. By applying the invention, an integral solution including vehicle, scheduling and signal systems can be checked and demonstrated; a signal system can be subjected to function and performance tests indoors, and failure injection conditions which can not be simulated in various sites can be carried out indoors, thus testing means are enriched and safety of the system is improved; and simulation checking under the condition of multiple vehicles can be passed, a method for analyzing the railway operation capability is deeply researched, and the reference is provided for the layout of signal devices.