In order to detect the location of fatigue cracks in engineering machin ery,this paper proposes a strategy to detect the location of cracks based on pulse echo method (Pulse-echo) using laser ultrasonic technology.The results show that by placing the detectio n source in the near-field region and simultaneously fixing the detection source and the excita tion source,the strategy of moving the material twice can make the position of the probe light r epresent the left and right edges of the crack during the two movements,so that The location wher e the crack is located and the width of the crack are obtained.Experiments show that this stra tegy can be used to locate the crack error.Compared with the traditional one-way moving sca nning method, the position information and the opening width of the crack can be obtained at t he same time. This paper provides a strategy for laser ultrasonic inspection of engineering ma chinery crack locations.