A traction control system for electric multiple units, provided to control the operation of inverter/four-quadrant power modules of a traction converter for electric multiple units, comprising a power supply module, inverter/four-quadrant modules, an I/O module, a network module, an MVB interface unit and a debugging module, wherein, the inverter/four-quadrant modules each comprise a computing board, a signal sampling board and a pulse interface board, bidirectional communication between the signal sampling board and the I/O module is realized by a first bus; bidirectional communication between the signal sampling board and the computing board is realized by a differential LinkPort bus; bidirectional communication between the computing board and a host processor, between the network module and the host processor, and between the debugging module and the host processor are realized by a CPCI bus; bidirectional communication between the I/O module and the inverter/four-quadrant modules is realized by the first bus; bidirectional communication between the I/O module and the network module, between the I/O module and the debugging module are realized by a CAN bus; the signal sampling board is configured to receive signals from an external sensor, receive second IGBT status signals sent by the pulse interface board and receive first control signals sent by the computing board, and send first IGBT control signals to the pulse interface board, send processed acquisition signals to the computing board, and send relay control signals to the I/O module; the computing board is configured to receive first analog signals and first digital signals acquired and processed by the signal sampling board, which are the said processed acquisition signals, and receive second control signals sent by the host processor, and send the first control signals to the signal sampling board and send processing signals to the network module; the pulse interface board can be connected to two groups of inverter power modules and two groups of four-quadrant power modules at most; the pulse interface board is configured to receive first IGBT status signals sent by the inverter/four-quadrant power modules and receive the first IGBT control signals sent by the signal sampling board, and send the second IGBT status signals to the signal sampling board and send second IGBT control signals to the inverter/four-quadrant power modules; the network module receives second digital signals and second analog signals sent by the I/O module and transfers the second digital signals and the second analog signals to the host processor via the CPCI bus; receives command signals from the host processor via the CPCI bus, and sends commands to the I/O module to control the I/O module to output third analog signals and third digital signals; controls data interaction between the MVB interface unit and an external MVB bus; and sends MVB data to the host processor via the CPCI bus, and sends data to be sent by the host processor to the MVB interface unit via the CPCI bus; the debugging module receives debugging commands and first debugging signals sent by the host processor via the CPCI bus; the debugging module receives second debugging signals sent by the signal sampling board via the CPCI bus; and, the power supply module supplies power to the inverter/four-quadrant modules, the I/O module, the network module and the debugging module.