The invention provides a 3RPS parallel robot geometry parameter identification method, and belongs to the industrial robot calibration technical field; the method comprises the following steps: building a work reference system B-xyz fixedly connected with a static platform and a local reference system P-x 'y 'z ' fixedly connected with a movable platform; building calibration coordinate system O-uvw using a double-shaft clinometer as a measuring instrument, planning measuring configuration, and building a constraint equation set compatible with a parameter identification equation set; using a MATLAB as a tool to solve to-be-identified parameter values. The method needs not to measure the movable platform pose information complete set, and can fully utilize the features that the double-shaft clinometers measuring precision of the movable platform rotary angle around x and y shafts has nothing to do with mounting position precision, thus reducing the parameter identification precision dependence on the measuring instrument mounting position precision.