Abstract: In order to improve utilization rate of crop straw, a kind of straw picking and crushing machine was designed which was suitable for multiple regions, especially for straw returning or collecting in the northwest arid region．The all-in-one machine included picking up device, crushing device and conveying device．Three devices installed on the same frame to improve stability of whole machine．SolidWorks software was used for solid modeling, ADAMS software was used for kinematic simulation of the model, by controlling pick up speed ratio to change movement trajectory of pick up roller, so as to obtain speed range of pick up roller with the best effect．EDEM software was used to establish straw-soil-machine interaction discrete element simulation system, and optimal speed of picking roller was deduced by comparing forward resistance of cutter roller in multiple simulation groups．Results showed that when forward speed of implement was 1 m/s and speed of knife roller was 1140 r/min, picking speed ratio was 15.73 and straw picking rate was α= 92.14%, at this time, resistance encountered by swinging knife during forward process was the smallest, and the machine has the best picking effect on scattered straw, with the lowest work energy consumption．