Among sexually transmitted infection (STI) pathogens, UU, CT, NG, and MG are very commonly detected. A retrospective study was conducted to analyze the clinical situations and laboratory data of patients in-fected with the four pathogens in Hangzhou city, Zhejiang Province, China. For this study, 4,716 female outpatients and inpatients of the Department of Obstetrics and Gynecology of Hangzhou Third People´s Hospital were randomly selected from January 2019 to December 2023. Multiple types of specimens were collected and four STI pathogens were detected. Data collection was taken from the hospital's electronic medical records and statistical analysis was processed with SPSS 25.0 software. In the past five years, year by year, the positive rate presented an increasing trend. Out of 4,716 patients, 2,931 were positive, and the positive rate was 62.15%. The positive rate of single infection was significantly higher than of co-infection (p < 0.05). The highest positive rate of all STI patients was found in the 20 age group, and the rate was significantly different between each age group (p < 0.05). Single infection with UU occurred significantly more often than with the other three pathogens (p < 0.05), and co-infection with UU and CT and UU, CT, and MG were significantly dominating (p < 0.05). Only three patients had an infection with all four pathogens, and it was extremely rare. The 21 - 30 and 31 - 40 age groups had high incidences of infection, with a significant difference compared with other age groups (p < 0.05). The positive rate shows an increasing trend in Hangzhou in the past five years. More single infection than co-infection and more younger patients were detected. Single infection with UU was dominant in all positive patients. The publicity and more screening testing items of STI for younger people should be strengthened in Hangzhou, and the people of Hangzhou should be made more aware that information technology is helpful in aiding the control of STI diseases.