The cause of thrust ripple of PMLSM is the detent force producing shake and noise, at the lower speed region, control performances become increasingly deteriorated. Distributing characteristic of the end component at holly journey in PMLSM was analyzed using finite element method. The effects of permanent magnet length and poles number adopting FFT cool on the end component were studied and relation curve was present comprehend in reason. Analysis results are benefit to design and operation of PMLSM.