The ironless long stator permanent magnet linear synchronous machine (IPMLSM) with Halbach Array is used in the medium and low speed maglev system. One of advantages of ironless linear synchronous machine is reducing the normal force to near zero, but the thrust decreases obviously because of ironless. In this paper, the relationship between the optimization variables and the steady-state performance parameters is studied by continuously changing the magnetic pole distance, permanent magnet height and rated current of the motor, and the influence of each optimization variable on the performance of the motor is clarified, which is convenient for the optimal design of the motor.