Abstract: With the more and more extensive application of portable cabinet, its miniaturization and high integration is becoming the trend, structural design problems follow as well, especially the heat dissipation problem becomes the key factor of its reliable work. This paper introduces the importance of thermal simulation analysis in today′s electronic equipment design, then carries out the thermal simulation analysis for certain portable cabinet by using numerical simulation software. The heat dissipation form of forced air cooling is adopted. Reasonable parameter setting and meshing of the simulation analysis model is conducted. By changing the structure of the air inlet, the temperature of the main power devices can be controlled below 85 ℃, which satisfies the demands of the cabinet thermal design and provides references for the thermal simulation analysis and design of other similar electronic equipment.