No less than four routine hysterosalpingogram films, with the following specific quality control criteria: 1. Pelvic localization films Requirement: standard orthopantomogram of the pelvis. Purpose: To observe whether there are foreign bodies and calcified shadows in the pelvis. Compare with the first film injected with iodine water to determine whether it is a tubal image, iodine water diffusion into the pelvis or pelvic bone cortical image, calcification and intestinal contents. 2. First film Requirement: The film can be taken after iodine injection. If the fallopian tubes are visualized, the alignment, morphology and peristaltic function of the fallopian tubes should be clearly shown bilaterally. Purpose: To observe whether the fallopian tubes are visualized and whether there is high tubal tension, stenosis, widening, dilatation, stiffness and uplift of the umbilical ends. To determine the degree of patency of the tubes bilaterally and whether there is tubal blockage, hydrocele, corymbal adhesions, etc. 3.Second film Requirement: The film can be taken after re-injection of iodine water and show the maximum cross-sectional area of the uterine cavity. Purpose: To further observe the morphology of the fallopian tubes dynamically, whether the tubes are waterlogged bilaterally and whether the iodine water collects at the umbilical end; to observe the size, morphology and edge of the uterine cavity; to determine the site of tubal blockage and the degree of patency of the fallopian tubes bilaterally. The maximum cross-sectional area of the uterine cavity shows the uterine cavity to observe whether there are uterine malformations, uterine adhesions, uterine polyps and fibroids, etc. 4.Delayed film Requirement: film taken after 20 minutes of iodine injection. Purpose: To observe the amount of iodine water diffused into the pelvic cavity, whether it is evenly diffused, whether iodine water remains and dilates in the bilateral fallopian tubes, and whether iodine water gathers in the distal fallopian tubes; to determine whether the fallopian tubes are suffering from patency, umbilical adhesions, fluid accumulation, tubulitis nodosa, pelvic inflammatory disease, etc. If the standardized HSG image quality control is not followed, there may be wrong or deviated tubal diagnosis and consequently treatment failure. Only by strictly adhering to the HSG imaging quality control standards can the function and patency of the fallopian tubes be correctly and objectively evaluated, thus providing a positive treatment for infertility caused by tubal problems.