Abstract: According to staus of the frecuent facture for planetary mechanismn ofcuting unit of MG2Q00/46-ND type sheare,using the testing of chemical composition and mechanical propertis.thetesting of microscopic srouctre and thefnie element analysis and on-sie inspecion analyzing from matera structure and use ofthe environment. The resutis showed that the planetary mechanismn of iMGC2Q00446-WD typeof shearer problems such as insufcient strength and stress concentratio.should be improved from the materals,process and the stucturedesign; the strength of planetary mechanism increased by 32% and maxinmum stress value decreases to58% aner improvementusin fiect verity the valdity of the improved scheme.The paer puts forward the improved method can effectivly improve the strength of planetary mechanism.lt can provide the reference for design and research of thin seam shearer planetary mechanism.