Abstract: In order to solve the problem of lack of signal equipment in the teaching of CTCS-3 train control system in colleges and universities, this paper established a CTCS-3 train control simulation experiment system suitable for teaching in colleges and universities in the form of software simulation. The paper focused on the trackside simulation subsystem in the CTCS-3 train control simulation experiment system, took the trackside equipment including track circuit, balise, signal, and turnout as the research object, proposed the overall design scheme of the trackside simulation subsystem, explained the detailed implementation of the internal core function, introduced the workflow of the system. The subsystem was jointly adjusted with other simulation subsystems of CTCS-3 train control simulation experiment system, and achieved the established functional requirements. The results show that the trackside simulation subsystem implemented by this design can better cooperate with the realization of the teaching of CTCS-3 train control system.