To understand the current status and progress of anal fistula imaging diagnosis. Methods A review of the literature on the current status and progress of anal fistula imaging diagnosis was conducted. Ultrasonography can accurately display the morphology of the lesion and save the image for postoperative research. However, the accuracy of the examination depends on the operator’s experience, technique and duration of the disease, and also on the length of the fistula, the maturity of the fibrous canal and the clarity of the ultrasound image, which is less intuitive. MRI has high soft tissue resolution, can directly image in three dimensions, and can acquire high quality images due to less movement of pelvic organs. Conclusion Traditional fistulography has been eliminated, and ultrasound, CT 3D reconstruction, and MRI are rapidly developing and are becoming important and even routine methods of fistula examination. Most fistulas can be diagnosed by clinical examination, but some complex fistulas and high-grade fistulas require imaging in order to clarify their course. Before the introduction of ultrasound and MRI, fistulography was a routine method for the diagnosis of anal fistulae, and it has great clinical significance and is still used in clinical practice. Fistulography also has many limitations. For example, fistulography cannot be performed when there is no external fistula, and when there is an internal or external fistula, the contrast agent can easily spill and affect the diagnosis. In addition, fistulography may cause bacteraemia or adverse reactions to the contrast agent due to pressure injection, which may cause bacteria and contrast agent to enter the bloodstream. In addition, this method can only obtain planar information, which makes it difficult to determine the morphology and course of the fistula and provides little information about the extent of tissue invasion near the fistula, thus providing limited preoperative assistance to the surgeon. The test also involves ionizing radiation, which is harmful and inappropriate for some patients, compared to other tests. Ultrasound examination: The use of transanal ultrasound examination method to diagnose anal fistula and perianal abscess has obvious advantages, such as ultrasound examination can accurately display the morphology of the lesion, and the image can be saved for post-operative research before and after surgery. Anal fistulas are mostly shown as hypoechoic cords with relatively clear margins on ultrasound images. Occasionally, the mass is a mixture of strong echogenicity and hypoechogenicity, with equally well-defined margins and honeycomb structures. Most of the abscesses are due to prolonged abscesses, fibrous tissue proliferation, and formation of luminal walls or canal walls. The cross-section is round or with round hypoechoic clusters. In early stages, the cavity with pus is cystic in nature, and in advanced stages, it is a heterogeneous mass with a mixture of hypoechoic and hyperechoic light with blurred margins. These hypoechoic or mixed masses communicate with the anus through a defect in the internal sphincter, which is also located at the dentate line, where the internal opening of the fistula is located.