The incidence of choroidal nodular synovitis is relatively low, and although it is a benign synovial inflammatory reaction, it presents with malignant hyperplasia. The main lesions of choroidal nodular synovitis are synovial hyperplasia and joint effusion and are characterized by erosion of bone, mostly in the large joints of the extremities, such as the hip and knee. The main lesions are limited or diffuse, and the main symptoms are significant swelling and pain in the joint and limited function. The diagnosis of villous nodular synovitis is mainly made by MRI and arthroscopy, and pathological examination is required after arthroscopic treatment to finalize the diagnosis. The main treatment option for villous nodular synovitis is surgical excision, which is required to be particularly thorough, otherwise it is prone to recurrence.