Objective To investigate the quantity, distribution, and occurrence dynamics of important vectors by emergency monitoring of vectors after flood in Jintang county of Sichuan province, China, and to provide a scientific basis for preventing and controlling the outbreak and prevalence of vector-borne infectious diseases after flood. Methods On July 12, 2018, the first day after flood, the densities of flies and rodents were observed in the flooded areas of Jintang county. A mosquito lamp was used to observe the density of mosquitoes, and the rodent trace method was used to observe the density of rodents. Results Mosquitoes and flies were the key vectors for biological control. After sterilization, the mean density of mosquitoes was 1.78 mosquitoes/lamp·hour, the density of flies decreased from 29.30 flies/m² to 6.44 flies/m², and the mean density of rodents was 0.66 places/km. Environmental health was restored and the breeding sites of mosquitoes and files were effectively controlled. Conclusion By summarizing and analyzing the data of vector monitoring after flood, we can first clean up the important breeding garbage and carry out accurate insecticidal control to guide prevention and control, so as to effectively prevent and control the outbreak and prevalence of vector-borne infectious diseases.