Permanent magnet linear synchronous motor (PMLSM) is a new type of motor with high positioning accuracy. This paper introduces the related design theory of PMLSM with the utilization of finite element software. we refer to the sample transient electromagnetic analysis, firstly. And then get the Thrust fluctuation map and compare to its winding back EMF curve and other related graphs. Through altering of the thickness, air gap length, junior core’s structure and size and other parameters, we finally conclude the designed requirements will be eventually fulfilled this optimization.