Abstract: The main influence factors on fatigue strength of thermal spraying crankshaft were analyzed. The stress case on the surface of test parts by wet blasting roughening and arc roughening were measured, and bond strength between coating and base were tetsed, the metallurgical structure of the coating was also observed. Results show that the bond strengths of the coating treated by two kinds of roughening method are almost equal and the stress case on the surface of the parts after wet blasting is more significantly excellent than that by arc roughening. 