Screw thread automatic detecting equipment and method

The invention relates to screw thread automatic detecting equipment and a method thereof; the main frame of the equipment is a fixing frame, a screw thread detecting pin is driven by a working air cylinder fixed at the center of the outer part of the top side to move downwards to carry out detection, a product detecting fixture is arranged on a base of the fixing frame, and the position of a screw thread hole of the product to be detected is arranged right below the screw thread detecting pin; a sensor is arranged at one side of the screw thread detecting pin, the front end part of the sensor is vertical to the screw thread detecting pin and is arranged at a distance from the screw thread detecting pin, the sensor is triggered to carry out detection by the insertion of a screw thread detecting rod at the front end of the screw thread detecting pin or by different working states generated by preventing from moving downwards. The equipment fully utilizes the difference of pore diameter of an extruding and tappi