The invention provides a three-axis linkage-based complicated part accurate measurement central path planning realizing method and a device. the device comprises a base, a workpiece vertical column, and a measurement vertical column, wherein the measurement vertical column is provided with an electric sensing head capable of moving vertically and horizontally. Horizontal movement of the measurement vertical column is used for contotrlling the distance between the measuring head and the center of a spindle rotating shaft system, stepless adjustment of a basic circle can be realized, a series of basic circle discs do not need to assist measurement of a gear, the detection process is simplified, and detection errors due to wear of the basic circle discs can be solved. Through controlling vertical movement, horizontal movement of the measuring head and linkage of the spindle rotating shaft system, control of the measuring trajectory of the measuring head can be realized respectively, and helix, tooth profile and pitch error of the gear with any base circle radius value within the measuring range can be fully automatically measured. In addition, path planning of an eccentric gear can be realized, and full-automatic measurement on helix, tooth profile and pitch error of the eccentric gear can be realized.