Air pipe dimension measuring device

The utility model relates to the technical field of air duct size measurement, in particular to an air duct size measuring device, which comprises a container, a measuring strip and a protection device, the measuring strip is mounted on the inner surface of the container, the protection device is arranged on the surface of the container and comprises a guide plate, and the guide plate is fixedly connected with the surface of the container. The guide plate is located above the measuring strip, and a sliding groove is formed in the surface of the guide plate and located above the measuring strip. According to the utility model, by arranging the protection device, a worker is effectively protected, and when the air pipe size measuring device is used, the extrusion block is adjusted, so that the condition that the worker slides when using the air pipe size measuring device to measure a material is avoided, and the practicability of the air pipe size measuring device is improved; the auxiliary performance of the a