Countersunk head angle gauge for counterbore and measurement method of countersunk head angle gauge

The invention provides a countersunk head angle gauge for a counterbore and a measurement method of the countersunk head angle gauge. The countersunk head angle gauge comprises a dial indicator, a sleeve and a gauge measuring head, wherein the sleeve comprises a hollow cavity; the cavity refers to a sleeve cavity; the gauge measuring head is arranged at the bottom of the sleeve cavity and is in sliding fit with the sleeve cavity; the bottom of the gauge measuring head does a telescopic motion relative to the bottom surface of the sleeve; and when the bottom surface of the gauge measuring head and the bottom surface of the sleeve are positioned on the same horizontal plane, a measuring head of the dial indicator is pressed against the top of the gauge measuring head, and the measuring head is positioned in a compressed state. According to the matched arrangement of the dial indicator, the sleeve and the gauge measuring head, the direct measurement of the countersunk head angle can be converted into length measurement, the efficiency of measuring the countersunk head angle is improved by using the countersunk head angle gauge, and the measurement accuracy is improved.