Objective To analyze the infection status of hepatitis C virus (HCV), human immunodeficiency virus (HIV) and syphilis among drug users in sentinel surveillance in Guiyang City, analyze the related influencing factors of HCV infection, so as to provide basis for targeted prevention and control of HCV infection among drug users. Methods Repeated cross-sectional survey was conducted among drug users in sentinel surveillance in Guiyang City from 2017 to 2019, different drug rehabilitation centers were surveyed each year, monitoring period was from April to July, venous blood was collected for detection of HIV, syphilis and HCV antibody. Infection rates of HCV due to different factors were compared and analyzed. Results From 2017 to 2019, a total of 1 186 drug users were surveyed, HIV infection rates in each year were 0.8%, 0.2% and 0.5% respectively, syphilis infection rates were 7.1%, 8.9% and 9.3% respectively, HCV infection rates were 40.9%, 46.4% and 46.3% respectively. Age ≥ 25 years old (OR=3.334-5.963), female (OR=1.487), sharing injection device (OR=8.107), injecting drugs in recent one month (OR=6.300) and positive syphilis antibody (OR=1.514) were risk factors for HCV infection in drug users. Conclusion In recent years, HIV infection rate among drug users in Guiyang City is low, but HCV infection rate is high, epidemic situation is severe, comprehensive prevention and treatment should be strengthened according to the related influencing factors for HCV in drug users.