Infection four refers to: hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibody (anti-HCV), human immunodeficiency virus HIV1+2 antibody (anti-HIV) and syphilis spirochete antibody (anti-TP) four tests, is one of the four infectious diseases mentioned above screening means. China is one of the countries with a high infection rate of hepatitis B. Although hepatitis B has been on the decline in recent years, the infection rate of hepatitis B virus in the population is still around 5%. Hepatitis C infection rate is also high, reported in the literature to be around 1%. In recent years, syphilis and AIDS epidemics have also entered a period of rapid growth, especially in individual provinces in the south of the country where syphilis and AIDS are highly prevalent, and the situation is particularly serious. Medical workers may come into contact with patients and their body fluids, blood, secretions, etc. every day, especially when performing surgery, injections, punctures, blood draws, cleaning and handling medical equipment often have sharp injuries, and it is entirely possible to be infected by the damaged or exposed skin and mucous membranes when they come into contact with the dirt. Health care workers in the process of diagnosis and treatment, due to needle stick injury caused by hepatitis C infection rate of 3% to 4%, hepatitis B for 4% to 5%, hepatitis B patients in the process of labor and delivery of about 1/3 infected to the newborn baby or later close contact and cause the baby’s infection. Instrument disinfection is not strict can make hemodialysis, gastroscopy, bronchoscopy, surgery and other patients with hepatitis B and hepatitis C infection rate is significantly higher than the normal population, while dental patients with hepatitis B infection rate is also higher than the normal population, which may be due to infectious diseases patients with oral mucosa, blood, saliva and dirt instruments and caused by medical cross-infection. China’s medical personnel serum HBsAg positivity rate is 3 times to 6 times that of the general population, which indicates that the precautionary consciousness of medical personnel is not enough, the occupational infection problem of medical workers should be given sufficient attention to the patient’s hospitalization or traumatic treatment before the first necessary examination, timely detection of positive patients, isolation and treatment and to remind the medical staff to strengthen self-protection, pay attention to the operation of medical process, reduce medical injuries. We also remind medical personnel to strengthen self-protection, pay attention to operation standardization in the medical process, and reduce medical injuries. Strengthening the management of screened positive patients is a necessary requirement to prevent cross-infection in the medical process. Many patients have low autoimmune function and are susceptible to new infections, and positive patients should be managed in isolation wards to prevent and avoid nosocomial cross-infection. Surgical instruments are also one of the pathways of viral infection. Instruments and various items that have been contaminated by known positive patients should be highly valued and strictly disinfected and sterilized. Disposable materials (e.g. syringes, specimen tubes, dressings, etc.) should be handed over to the medical waste recycling station for centralized incineration after strict disinfection, so as to reduce and avoid transmission and spread of viruses inside and outside the hospital. Since the establishment of blood centers around China, the quality of blood has been strictly controlled, unified management to ensure the safety of blood transfusion, and now the possibility of infection through blood transfusion is greatly reduced. However, the preservation of the original data of the four test results of patients’ infection is an important basis for the reversal of proof in the medical process, so as to find out the reasons and distinguish the responsibility when medical disputes occur in the future, and to provide legal information and evidence for dealing with the disputes between doctors and patients. In summary, by first conducting the four indicators of infection test for hospitalized patients, not only can we understand the infection situation of the patients, carry out relevant treatment for positive patients, which is conducive to the recovery of the patients after surgery, but also can carry out the self-protection of health care personnel, and save the evidence of the medical process, which is of great significance to the patients, medical personnel, and control of nosocomial infections.