The utility model relates to a torque parameter measuring apparatus for a permanent magnet synchronous motor (PMSM). The torque parameter measuring apparatus is used for measuring the torque parameter of a PMSM and comprises a DC voltage-stabilizing power supply, an inverter, a driving controller, an encoder, a torquemeter, and a dynamometer. The dynamometer is connected with the output shaft of the PMSM through the torquemeter. A current and rotating speed double closed loop control system is formed between the PMSM and the encoder, and between the driving controller and the inverter. The inverter is connected with the DC voltage-stabilizing power supply. In view of the influence of parametric variation on torque estimation in a motor operating process, using a PMSM vector control algorithm, the torque parameter measuring apparatus decomposes three-phase current on a d axis and a q axis with PARK transformation. The current on the d axis and the q axis is controlled through lookup so as to achieve a purpose of accurately controlling the output torque of the motor. Parameters in a table are obtained by actual measurement so that high control precision is achieved.