Abstract: Modular multilevel matrix converter（M~3C） is currently the main power electronic equipment for frequency conversion in flexible low-frequency transmission systems. M~3C contains 9 bridge-legs and is widely used in high-voltage and high-power situations with a large number of series modules, which poses the special testing requirements for the production of its equipment submodules. On the basis of analyzing the steady-state voltage and current of M~3C bridge-legs, a pull-push operation test system is designed for several series bridge-leg submodules（valve sections）, which can perform equivalent power operation tests to assist in the production and factory testing of M~3C equipment. A control strategy for the pull-push test system is proposed, and a valve section push-push test system consisting of two sets of four series submodules is constructed and verified through relevant experiments. The experimental results show that the proposed test system can meet the equivalent power operation test of M~3C bridge-leg series submodules, and does not require high power consumption from the power source.