In this paper, self-assembly of agricultural machinery moving cars, for example, the use of CAD software ABAQUS software,the structural rigidity of the crank shaft diesel truck and modal characteristics do finite element analysis and experimental modal analysis as validation comparison。 This paper established using ABAQUS finite element model of the crank shaft, crank shaft stress results obtained by calculation found that load 350kN (step_time = 0.35),the maximum Mises stress (in the crank shaft main journal fillet) for 294.3MPa,If the load continues to increase,the maximum stress is beyond the scope of material to work properly。 Use fatigue analysis software FE-SAFE read stress results obtained contours and overall life expectancy distribution of hazardous areas, the use of drive shaft fatigue design formula than the test results。