Objective To examine the effect of JWX-V thermal fogging insecticide against mosquitoes, flies, and cockroaches. Methods The insecticide was diluted to prepare 1% oil formulation and applied by aerosol spraying at doses of 1, 2, 3, and 4 ml/m³ in the laboratory simulation field. After 30, 60, 90, and 120 min of treatment, the knockdown and mortality of the three kinds of insects were examined. For field test, 3 ml/m³ oil formulation was applied by aerosol spraying for 60 min, and the mortality of the insects was then measured. Results In the laboratory test, the effect of the insecticide against the insects was proportional to the dose of drug and the duration of action. Under the action of 3 ml/m³ insecticide applied by aerosol spraying for 60 min, the 60 min knockdown rates of the three kinds of insects were all >95% and their 24 h mortality rates were 100%. In the field test with 3 ml/m³ insecticide applied by aerosol spraying for 60 min, the average 60 min mortality rates of mosquitoes and flies were 100% and 96.07% respectively, and the average 24 h mortality rate of cockroaches was 95.06%. Conclusion JWX-V thermal fogging insecticide has a good fumigant effect lethal to mosquitoes, flies, and cockroaches.