The invention discloses a three-dimensional morphology detection and welding seam inflection point identifying method for multilayer multiple welding seams of a robot. The three-dimensional detectionand welding seam inflection point identifying method comprises the following steps that 1, a camera, line structural light and the robot are calibrated; 2, a welding seam structure light image is obtained and processed; and 3, the three-dimensional spatial morphology of the multilayer multiple welding seams is obtained, and inflection point characteristics are identified, specifically, the processcomprises the following steps that 3.1, the eigenvector of a calculated hessian matrix during extraction of a center line is recorded; 3.2, according to the direction of the eigenvector, the threshold value of the eigenvector difference is set to identify inflection points of the multilayer multiple welding seams; and 3.3, according to model data calculated in the step 1, the sub-pixel coordinatevalue of the center line under a camera coordinate system is converted to be under a robot coordinate system and serves as the three-dimensional data of the welding seam surface for being used for robot welding. According to the three-dimensional detection and welding seam inflection point identifying method for the multilayer multiple welding seams of the robot, the precision is high, the reliability is high, and real-time performance is good.