The invention discloses a permanent magnet synchronous motor control system and method with high control accuracy. The permanent magnet synchronous motor control system comprises an inverter circuit,absorption circuits and a voltage comparator, wherein the inverter circuit consists of three pairs of upper and lower bridge arms; the absorption circuits are arranged at both ends of each bridge arm;for each absorption circuit, a second switch Tk an a first capacitor C1 form a first series branch, a third resistor R3 and a second capacitor C2 are connected in parallel to form a first parallel branch, a third switch Tc, the first parallel barnch and a second resistor R2 are sequentially connected in series to form a second series branch, the first series branch and the second series branch are connected in parallel to form a second parallel branch, and the first switch Td, the first resistor R1 and the second parallel branch are sequentially connected in series; the in-phase input end ofthe voltage comparator is connected with voltages of both ends of the third resistor R3; the inverting input end of the voltage comparator is connected with voltages of both ends of the second capacitor C2; and the output end of the voltage comparator is connected with the control end of the second switch Tk. The invention effectively solves the technical problem of limited control accuracy on a permanent magnet synchronous motor.