Limiting dimension testing fixture

The utility model relates to the technical field of optical fiber communication device detection, and provides a limiting size detection tool, which is used for detecting the distance between the opposite end surfaces of an optical receiver and a tube shell in an optical transmitting and receiving assembly, and comprises a reference table and a limiting assembly. A positioning protrusion and a limiting assembly are arranged on the reference table, the opposite sides of the positioning protrusion and the limiting assembly are parallel to each other to form a limiting distance, and the limiting distance can be set to be the upper limit size or the lower limit size of the distance between the opposite end faces of the light receiver and the tube shell. Products meeting the size requirement are selected, personal errors in the processes of manual reading, manual clamping of the detected products and the like are avoided, and the accuracy of the detection result is improved. The limiting assembly can move in the d