_{In order to ensure the image quality, improve the efficiency and reduce the cost of detection, it is necessary to select the appropriate radiograph according to the specific situation in the process of liquid rocket engine product ray detection. In this paper, the characteristics and quality stability of imported Fuji IX100 film and domestic Lekai L7 film were compared, the results show that the background haze of L7 film is slightly higher than that of IX100 film ,the sensitivity is lower than that ofIX100 film, and the tolerance is higher than that of IX100 film; However, both of them belong to T3 category film specified in GB/T19348.1-2003, and their comprehensive properties are relatively close; L7 film is suitable for X-ray inspection of aluminum castings with variable cross-section, steel castings with small machining allowance, titanium castings and most of fusion welds on engines.}