Abstract: In well control operation，the high speed and high pressure fluid impacts erosion resistance device，generates pulsating
cycle impacting load and easily leads to the impacting fatigue. According to fatigue life theory，we make calculations
and find out the point where the erosion resistance device meets fatigue strength requirements. Afterwards，according to the
S 􀀀 N curve of the material，we carry out the fluid-solid interaction analysis and get the load spectrum acting on the erosion
resistance device based on ANSYS Workbench platform of multi-physical interaction analysis. Fatigue analysis software Ncode
DsignLife is used to accomplish the numerical simulation of fatigue life of the erosion resistance device，and the fatigue safety
coefficient is presented as fatigue strength failure evaluation standard in the paper. We also find out that the safety factor about
the key region of the erosion resistance device is greater than 1，the requirements about fatigue strength design are met，and the
cloud chart of safety factor and stress distribution are in the same position，which means that the numerical simulation results
have some guide significances.

Key words: erosion resistance device, fluid-solid interaction, fatigue life, impact fatigue, Workbench