The invention provides a detection tool used for detecting a support in the middle of an automobile beam. The detection tool used for detecting the support in the middle of the automobile beam is high in performance cost ratio, simple in operation and comprehensive in detection. According to the detection tool used for detecting the support in the middle of the automobile beam, a notch is formed at the top end of an operating table, the bottom face of the notch is a downwards inclined slope face, long-shaped holes are formed at two ends of the bottom face of the notch, the lateral faces of the notch are vertical faces with two ends downwards extending, the bottom face of the notch and the lateral faces of the notch are matched with an outer contour of the support in the middle of the automobile beam, and a detecting open hole corresponding to the detected support in the middle of the automobile beam is formed in the bottom face of the notch. According to the adoption of the structure, an originally used three coordinate measuring machine which is used for detecting whether a part is qualified or not is abandoned, the three coordinate measuring machine is quite high in price, complex in operation and high in requirement for an operator, a standard measurement does not need to be located for multiple times, coordinates do not need to be converted for multiple times, the disadvantage that due to low measurement efficiency, the production requirement is difficult to meet is overcome, detecting cost is greatly reduced, and the detection tool used for detecting the support in the middle of the automobile beam is particularly suitable for detection of mass-produced parts in industry.