The invention relates to a method and a device for detecting intensifying coefficients of an intensifying screen for radiographic inspection. The method comprises the following steps of: performing transmission on a step block (4) to which films (3) are adhered by an X-ray machine (1) under tube voltage of 180KV at a focal length of 600mm; placing the films (3) in a developing solution and developing; placing the developed films (3) in a water channel and washing; transferring the washed films (3) into a fixing solution and fixing; placing the fully fixed films in flowing clear water and washing; and performing blackness detection on the films (3) with the intensifying screen (2) and the films (3) without the intensifying screen (2). By the method and the device for detecting the intensifying coefficients of the intensifying screen for radiographic inspection, one-time exposure and one-time darkroom treatment are performed, a plurality of films which use the intensifying screens and do not use the intensifying screens and have different blackness are obtained simultaneously, and the blackness ratio is directly obtained; and the method and the device are easy to operate, and have quick and good detection effects.