The invention provides a laser machining and locating method. The method comprises the steps that a laser machining and locating system is constructed; a mechanical arm grabs a detection head and installs the detection head at the tail end of the mechanical arm; a computer control system and the detection head are utilized for carrying out initialized location on blades of an aviation engine, andlocating coordinate data are obtained; the mechanical arm grabs a laser machining work head and installs the laser machining work head at the tail end of the mechanical arm, the computer control system and the locating coordinate data are utilized for converting the laser machining work head into a coordinate system determined by the locating coordinate data, and then laser emitted by the laser machining work head begins to be utilized for carrying out machining. The method has the effects that by means of location of a sensor controlled by a computer, three-dimensional coordinate modeling canbe carried out in the laser machining process, the computer is utilized for dealing with and converting coordinates to locate the machined blades of the aviation engine, thus the defects that duringtraditional laser machining, locating stability of visible light is poor, and precision is low can be overcome, meanwhile, the disturbance resisting ability of sensor location is high, and combinationwith the laser machining technology can be well achieved.