Abstract: Aiming at the problem that the martensite steel forgings for helicopter are prone to crack, the effects of pickling, sand blowing and annealing on the crack of forgings were analyzed, and the mechanism and evading method of forging crack were explored. It is found that when the surface of martensite steel forgings is directly pickled after forging,obvious surface cracks are found by fluorescent magnetic powder detection. The longer the pickling time, the longer the crack is. After sandblasting or annealing and then acid pickling, there are no cracks on the surface of the forgings. The causes of surface cracks in martensite steel forgings are mainly related to the residual stress on the surface of forgings. Because of the high residual stress on the surface, cracks are easy to occur after pickling of forgings. After blowing sand or annealing, the surface residual stress decreases and no cracks occur after pickling.