Study results on the supercharged boiler numerical simulation are on the boiler, convection tube bundle or the super-heater. These study subjects in a single model, and simplified the boundary condition to a certain extent. This paper takes the boiler as a whole research object. On the furnace chamber for combustion simulation, using the profile boundary information file boundary condition setting, faithfully transmitting boundary parameter spatial distribution. Followed by the simulation of heat transfer between the convection tube bundle and super-heater modules, we can get a real fluid flow and heat transfer condition, thus reacting to the complex heat transfer and flow inside of boiler, knowing the distribution of temperature, speed, pressure and other parameters. We can also see the change rule of the combustion and heat transfer processes in that supercharged boiler. Then we discuss the impact of the not uniform heat load on the convection heating surfaces, and preliminary analyzes the mechanism of combustion and heat transfer in supercharged boiler.