Measuring element, measuring method and measuring device for detecting arc-shaped surface depression depth

The invention belongs to the field of precision measuring instruments and equipment, and provides a measuring element, a measuring method and a measuring device for detecting the arc-shaped surface depression depth. The measuring device for detecting the arc-shaped surface depression depth comprises a measuring part, the measuring part comprises a main measuring head and two auxiliary measuring heads, and the two auxiliary measuring heads are arranged on the two sides of the main measuring head at equal intervals; the axes of the main measuring head and the two auxiliary measuring heads are always coplanar; and a data processing part which is used for obtaining the linear displacement of the main measuring head extending into the tread recess, calculating a measurement error according to the distance between the auxiliary measuring head and the main measuring head and the radius change of the circle where the arc-shaped surface is located, correcting the linear displacement of the mainmeasuring head and obtai