Angle measuring device

The utility model provides an angle measuring device which comprises a contact assembly, a measuring assembly and an angle detecting mechanism, the contact assembly comprises a first plane and a second plane which are respectively arranged on a first contact part and a second contact part, and the measuring assembly comprises a first datum line and a second datum line which are respectively arranged on a first rod body and a second rod body. The first datum line is perpendicular to the first plane, the second datum line is perpendicular to the second plane, the angle detection mechanism is used for obtaining the degree of an included angle between the first datum line and the second datum line, and the included angle between two radiuses of two tangency points passing through the arc is a central angle according to the principle that the radiuses of the tangency points passing through the arc are perpendicular to a tangent line of the tangency point. The degree of the included angle between the first datum li