The DC traction power supply system of the metro system is very likely to produce some stray currents, prevent this harmful stray current would cost a large amount of money and the final consequence not always as we expected. In addition, metro’s DC traction power supply lead to it cannot be connected with high-speed railway and intercity railway lines. So come up with a new kind of AC traction power supply system is an irresistible trend. However, during the process of the three-phase current transform to the single-phase current, the power supply system would produce negative sequence current, the negative sequence is also harmful to the whole traction system, as a consequence, is very meaningful to design a metro AC traction power supply system which based on the negative current eliminating controller. The paper showed the construction design of the metro AC traction power supply system which based on the negative current eliminating controller. First, the paper focused on the mathematical model and topological structure of the PWM rectifier, because the negative current controller is mainly based on the three-phase PWM rectifier. Then designed a double loop control system which enabled eliminate the negative current, add the data and the whole structure of the AC traction power supply system into this negative sequence current eliminating controller, observe the negative current result. Finally, in order to prove the method is right and the validity of the design, the author used the Matlab software to build the whole metro AC traction power supply system which based on the negative current eliminating controller, and obtain the satisfactory result.

CICTP