Objective To compare COVID-19 epidemic detection strategies and test results at different stages,and provide technical support for epidemic prevention and control. Methods The COVID-19 epidemic in Lu'an from January 20,2020 to February 20th was divided into three stages.Different throat swabs samples were collected from different stages.4088 samples were collected and real-time coronal fluorescence RT-PCR was used to detect new coronavirus nucleic acids. Results From January 20 to February 20,2020,4088 throat swab samples were detected in Lu'an City,including 492 suspected cases and 3596 key population samples.69 cases of covid-19 were diagnosed and 10 cases of asymptomatic infection were detected.The positive rate was 1.93%.The positive detection rate of suspected cases (14.0%) was higher than that of key population (0.4%) (χ²=398.166,P＜0.05).The positive detection rate of suspected patients in the first stage (25.8%) was not significantly different from that in the second stage (20.8%) (χ²=0.735,P＞0.05).The positive rate of suspected patients in the second stage (20.8%) was higher than that in the third stage (3.7%) (χ²=28.775,P＜ 0.05).The positive rate of the second stage was 0.9%,higher than that of the third stage (0.2%) (χ²=9.954,P＜ 0.05). Conclusion Lu'an City adopted the detection strategy according to the epidemic situation in different stages,so that the epidemic situation has been better controlled.Prevention and control measures should be maintained,and strengthen the screening of fever patients,returnees,entry personnel,medical staff and delivery personnel who may play a high transmission role.