Abstract: Working principle of existing classifier was combined，a comprehensive analysis of advantages and disadvantages of various types of classifier was done.According to actual working situation，grid cylinder dried fruit sorting machine was designed，overall design of strip roller type classifier was completed，and structure and working principle were introduced.Key parts such as classifier drive system，grid roller screening device and blade adjusting device were designed.Key parameters such as drum speed，grid clearance，lifting angle were calculated.Through design of grate drum classifier and parameters calculation of key components，it could provide a reference for further study and optimization of dry fruit classifier.