Small-Abbe-error three-dimensional measurement system

The invention discloses a small-Abbe-error three-dimensional measurement system, which is characterized in that the small-Abbe-error three-dimensional measurement system is arranged in a mechanical transmission unit and comprises an X-direction assembly, a Y-direction assembly and a Z-direction assembly, a Z-direction clamp head used for clamping a sensor is fixedly arranged on a Z-direction slide seat arranged in the Z-direction assembly, and gratings consisting of grating rulers and grating heads respectively comprise an X-direction grating assembly, a Y-direction grating assembly and a Z-direction grating assembly. The small-Abbe-error three-dimensional measurement system has the technical effects of high efficiency, accuracy and simplicity when being applied to the thermal deformation detection, and the Abbe errors can be effectively reduced.