A laser welding teaching device, and a teaching method, for simplifying the teaching of the motion of a scanner and for reducing a welding operation time by a welding robot. The laser welding teaching device is connected to a robot control device for controlling the welding robot for welding a workpiece and sends a command to the robot control device. A laser oscillator is connected to a work tool of the robot and a laser scanner is mounted on the work tool. By using the laser scanner capable of moving at high-speed, the motion of the robot during the air cut motion may be greatly reduced, resulting in a significant reduction of the cycle time of the whole system.