The utility model relates to a height detection instrument between differential side gear hole terminal surface and excircle terminal surface, including standard flat board, positioning disk, highly comparison gage block, percentage table, table skeleton. On standard flat board is arranged in to the positioning disk, high for the comparator gauge screw fixed with the positioning disk. The utility model discloses the measurement examines that a simple structure, manufacturing costs are low, the lay day is short, positioning accuracy is high, makes things convenient for the detection of differential side gear hole terminal surface and excircle terminal surface interval, provides the guarantee for differential side gear's processingquality control.