Abstract: Aiming at the problem that the mechanical vibration caused by the linear motor affects the accuracy of the special-shaped plug-in machine, the vibration characteristics of the special-shaped plug-in machine were studied, and the structure was optimized according to the vibration characteristics. Firstly, the thrust and frequency tests of the linear motor on the special-shaped plug-in machine were carried out. Secondly, the modal analysis of the whole machine model of the special-shaped plug-in machine was carried out, and the structural optimization of the parts was carried out according to the modal analysis results, so as to improve the low-order natural frequency of the special-shaped plug-in machine. Then, the harmonic response analysis of the optimized whole machine model was carried out, and the amplitude-frequency response data of the sampling point is calculated. Finally, the vision camera was used to test the repeatability of the special-shaped plug-in machine. The results show that the first six natural frequencies of the optimized special-shaped plug-in machine have different degrees of improvement, and the vibration displacement of the sampling point was about 0.03 mm under the excitation of the linear motor of 0~50 Hz. The experimental test was that the repeatability of positioning was stable within ±0.03 mm, which verifies the effectiveness of structural optimization and the reliability of simulation results.