Abstract: In view of the continuous separation problem of respirable dust, the separation methods of ceramic, inertial impact and whirlwind were analyzed. The fluid dynamics software Fluent was used to conduct numerical simulation of the flow field inside the virtual impactor, the virtual impactor model meeting the BMRC curve separation standard was established, and the structure size of the separator was modified and optimized combined with the numerical simulation results.According to the model, the separator sample was processed and verified by aerosol experiment. The results show that the separation efficiency standard deviation between the sample and the BMRC curve is less than 5%, meeting the requirements of the industry standard.