Connecting rod keyway angle detection device and detection method

The invention discloses a connecting rod key groove angle detection device which comprises a detection tool base. A positioning mechanism for positioning a connecting rod workpiece is assembled and connected to the top of the detection tool base; the device further comprises an angle detection mechanism. The angle detection mechanism comprises a fixing frame, a detection rod capable of being adjusted in a lifting mode is assembled and connected to the fixing frame, and an angle ruler for detecting an included angle is slidably assembled and connected to the top of the detection rod. The angle detection mechanism further comprises an auxiliary plate matched with a key groove in the connecting rod. In the detection process, the auxiliary plate is located in the key groove. The bottom of the detection rod is slidably connected with a detection tool assembly used for contrasting and detecting a large hole in a connecting rod workpiece. The testing fixture assembly comprises a testing fixture rod, the bottom of th