To solve the problem that each motor can operate independently by the same DC bus power, in the multiple multi-phase motor drive system, a number of multi-phase motors can be series connected and driven by a single inverter via the appropriate phase transformation rules, and all motors in series can be independently controlled. Taking two double Y shift 30° permanent magnet synchronous motor (PMSM) series system as example, the vector control strategy of id=0 and the carrier modulation PWM technology are adopted to control the two motors. Simulation of the two motors series system is obtained based on Matlab/simulink and the results show that these two motors can be decoupled controlled by a single inverter. The research can provide a reference for the depth study of multi-phase motor series system.