In order to improve the hydraulic performance and anti-clogging performance of Y-type screen filter, taking the angle between outlet and cylinder, the inlet reduction ratio, the height of guide vane and the center angle of guide vane as experimental factors, the filtration process inside the filter was studied by the method of CFD-DEM coupling and physical test. Through the range analysis of a series of numerical simulation orthogonal test results, the sensitivity of various factors to water head loss, area proportion of medium speed flow area, relative standard deviation of particle distribution and interception rate was explored. The results showed that the medium and high speed flow areas were concentrated on the exit side, and the exit cross-sectional area was positively correlated with it when the angle between the outlet and the cylinder was small, and the larger the corresponding medium-speed flow area was, the better the hydraulic performance was. The concentration of particles through the region corresponds to the medium-speed flow area, and the increase of the inlet reduction ratio made the more uniform particle distribution, the better the anti-clogging performance can be. The combination of structural optimization parameters was as follows: the angle between outlet and cylinder was 35°, the inlet reduction ratio was 22/26, the height of guide vane was 10mm, and the center angle of guide vane was 90°. Among them, the included angle had the most significant influence on the comprehensive index, which was the key parameter of structural design. Compared with that before improvement, the head loss was reduced by 36.6%, the relative standard deviation was reduced by 43.26%, the interception rate was increased by 3.93 percentage points, and the area proportion of medium-speed flow area was increased by 15.77 percentage points, which showed the effectiveness of the optimization scheme. The research results can provide some reference for the optimal design of screen filter.