The items of blood test for tooth extraction are generally blood routine, coagulation function test and infectious disease examination, etc. The following are the details: 1. Blood routine: mainly check whether the patient has anemia, infection or signs of thrombocytopenia and other possible systemic diseases. Because tooth extraction is an invasive operation, there will be bleeding, inflammation in the body will lead to aggravation of infection, and low platelets will cause more than bleeding, resulting in heavy bleeding. Anemia, low white blood cells and poor overall health status will also affect the recovery of the extraction wound, and it is only when the physical condition is basically stable that the patient is suitable for extraction. This examination has a certain influence on the preoperative preparation, intraoperative operation and postoperative disinfection, and can effectively prevent the occurrence of nosocomial infection by clarifying whether the patient has infectious diseases. If the patient has any abnormality in the index, it is recommended to go to the relevant department for detailed examination and treatment first, and to control the disease before the extraction surgery, which can effectively prevent the occurrence of surgical risks. If the interval between extractions is short, the infectious disease examination does not need to be repeated.