In this work we perform two models of Permanent Magnet Linear Synchronous Motors (PMLSMs). Both are analyzed by finite element method with different position angles of the magnets which are called skew angles. This article proposes a technique to determine the maximum and minimum levels of vibration produced by the presence of ripple on the thrust of PMLSM by the interaction between magnets and stator slots and the harmonic magnetic flux density in the air gap. The technique is defined by the analysis of the vibration signal produced in the PMLSM, applying the Fast Fourier Transform (FFT) with spectral analysis technique, as the application to rotating machines, to see which is the skew angle that produces lower levels of vibration.The proposed numerical model was analyzed with commercial software Flux ™ using the finite element method. The data analysis of vibrations caused by variations in the thrust of the model is done with commercial software MatLab ™.