Abstract: We addressed the cooling of electronic devices inside the vacuum isolated cavity set-up,comprising the fan,air-conditioner,vortex flowmeter,baffle and enough air.The flow fields of heat and air in the cavity was empirically approximated,mathematically formulated in standard k-ε model,theoretically analyzed in heat ventilation theory and numerically simulated with COMSOL Multiphysics software.The influence of the cavity structure and vent position on the heat dissipation was investigated.The simulated results show that the position and alignment of cylinder baffle and vent have a major impact.To be specific,the cylinder baffle divides the cavity space into two parts with the inner part containing the electronic devices.The baffle and the vent,installed at the optimized position,significantly increase the heat dissipation efficiency,because formation of good air-path significantly promotes ventilation and effectively improves air-cooling of electronic devices.