Patients with systemic lupus erythematosus (SLE) are prone to various infections due to autoimmune defects and long-term use of immunosuppressive agents. Mycobacterium tuberculosis (TBC) infection is a common infection in patients with SLE, especially in developing countries such as China. SLE and TBC may overlap and confuse a clinical picture, bringing great difficulties for the diagnosis and treatment. This article reports a case of vesicorectal fistula caused by intestinal TBC complicated with SLE, where the manifestation was recurrent diarrhea, initially treated as lupus-associated intestinal vasculitis without notable response. This case suggests that we should pay attention to close monitoring of tuberculosis-related indicators during the follow-up period of SLE patients, especially in endemic areas, and early diagnosis and treatment of TBC can reduce tuberculosis-related complications and significantly improve the quality of life of patients.