Abstract：In order to analyze the actual stress condition of the key parts of the transmission system of hose reel irrigators, and to estimate the fatigue life, the structure fatigue life prediction method based on the multibody dynamics simulation and Finite Element Method(FEM)was proposed, and the worm drive system fatigue life was predicted with this method as an example. The virtual prototype simulation model of the main components of the transmission system was established.The dynamic load histories of the worm drive system were evaluated by applying the ADAMS multibody system analysis technique; the fatigue life of gear, bearing and chain of transmission system was estimated by the Software ANSYS stress-based safety factor technology, which includes static strength and life estimation. Simulation results show that the resultant force of gear 16 is 5 392 N, the maximum theoretical force is 5 526 N, and the simulation error is 2.42%; the bending fatigue life value of gear 16 is 2.34×10<sup>5</sup>.The maximum radial force of bearing 8 is 1 685 N, and the fatigue life is 1.12×10<sup>5</sup> h. The average link peak in the range of 0-1 s tension is 11 837.2 N, the theoretical calculation value is 12 012 N, the actual calculation error is 1.45%. The error between the simulation value and the theoretical value is very small, which indicates that the simulation method can be used to diagnose the causes of fatigue accidents, and can serve as the basis for strengthening measures.
