This research content is design and analysis of twins cycloid reducer. Dismantle and draw the cycloidal reducer SPINEA which is made by Slovakia. Consult the inside structure, reduce the number of parts, change the traditional pin of pin wheel to teeth bite inside and outside, and cut the reduction ratio. Use the reverse engineering equipment to scan and find the contour of special shape of parts, then build CAD image by software Solidworks. At last, use plug-ins COSMOSMotion and COSMOSWorks to do the dynamic simulation and structural analysis, then give three different kinds of motion situations to adjust load value, speed value and change to the harmonic motion. Discussion may focus on the influence under different work factor of the whole structure.