Some pieces of key mechanical equipment were optimized to improve the stress distribution of equipment for the requirements of lightweight coal mine equipment. In this paper, the fiber filter of mine water purification station was taken as the research object and SolidWorks was used for parametric modeling. By using Workbench, the maximum stress value of the fiber filter under static load was obtained. The outer wall thickness of the filter spherical tank was optimized by the mothod of Screening optimization. Simulation research results show that under the same bearing pressure, the lower cylinder wall thickness of the fiber filter was optimized from 12 mm to 11.2 mm, and the wall thickness was reduced by 6.67%. The inner diameter of the upper spherical storage tank was optimized from 550 mm to 555.77 mm, and the wall thickness was reduced by 5.77 mm. The total mass of the filter decreased from 553.15 kg before optimization to 392.79 kg, which was reduced by about 29%. Optimization effect on the structural lightweight was obvious.