Machine tool space position precision testing device and testing method

The invention provides a machine tool space position precision testing device and testing method, and relates to the technical field of machining detection. The device comprises a measuring system which is arranged on a workbench of a machine tool to be measured and comprises a base, a trapezoidal lead screw, a guide rail, a guide column, a hand wheel and a supporting plate; wherein the base is connected with a machine tool to be detected through screws, and the supporting plate is connected with a detection support of a detection system through screws; the detection system is arranged on the measurement system, comprises a detection ball and is arranged on a machine tool spindle to be detected through a cutter handle; the detection support is arranged on the plane where the position 1, the position 2, the position 3 and the position 4 of the supporting plate are located; the capacitive sensor is connected with the detection bracket through a screw; the capacitive sensors include a first capacitive sensor, a