The utility model provides a piston blank head thickness and outer pin boss interval detection device. The piston blank head thickness and outer pin boss interval detection device comprises a base. The top surface of the base is provided with a horizontal through groove through which a piston blank head riser penetrates. Inverted L-shaped detecting tools are arranged on the positions, at two sides of the horizontal through groove, of the base. Each detecting tool comprises a detecting tool horizontal part used for detecting a piston blank outer pin boss interval and a detecting tool vertical part used for detecting a piston blank head thickness, wherein the horizontal distance between the detecting tool horizontal parts on two sides is matched with the piston blank outer pin boss interval in size, and the vertical distance between the detecting tool vertical parts on two sides is matched with the piston blank head thickness in size. According to the utility model, the inverted L-shaped detecting tools are utilized to detect the piston blank head thickness and the outer pin boss interval, the detection time is shortened, the detecting tool are highly-efficient and multi-functional, all detection requirements are met, and the quality of a piston is ensured.