It aims to realize the laser quenching and cladding for the principle axis and crank of single or more crank while the crankshaft is laid horizontally and rotating around the principal axis. The track of the laser spot is deduced when the laser acts on the surface of the crank and forms whorl line. According to the motion characteristic of 802D numerically-controlled machine tool in four axes linkage generally used for laser quenching, with the arc interpolation method, the numerically controlled programme for laser net veins quenching is made in the form of four axes linkage. With this, the net veins laser quenching and surface cladding for crankshaft are accomplished on the four axes linkage laser machine tool, when the crankshaft is laid horizontally and rotating around the principal axis. Because the principal axis is rotating at a constant speed, no balance iron is needed to locate the workpiece, the work process is steady, only one time of location is needed, and no more movement of the rotating axis is needed to accomplish laser quenching and cladding of the crankshaft with single or more cranks, which puts the ability of the above machine tool for laser quenching to good use.