Automatic coupler detection device and detection method

The invention discloses an automatic coupler detection device and a detection method. The device comprises a positioning shaft and a template body assembly, the template body assembly comprises a template body, an upper protective pin circular plate and a lower protective pin circular plate, and the upper protective pin circular plate and the lower protective pin circular plate extend to form circular plate limiting surfaces matched with coupler knuckle limiting surfaces. When the method is used for detecting the coupler knuckle, the template body is sleeved from the back side of the coupler knuckle, the template pin hole is aligned with the coupler knuckle pin hole, then the positioning shaft is inserted, the rear end of the template body rotates to the front side of the coupler knuckle around the positioning shaft, the circular plate limiting surface on the pin protection circular plate is in contact with the coupler knuckle limiting surface when the template body rotates to a limit position, and the plane