(1) platform simulation microwave oven heats up with Ansoft Corporation's electromagnetic field simulation software HFSS10.0, research microwave thermal reaction; (2) changes the microwave oven furnace chamber the size, carries on the simulation; (3) changes the coefficient of dielectrical loss Epsilon size. Carries on the simulation; (4) establishes the lamination model, carries on the simulation: (5) carries on the analysis in view of the simulation result, how to achieve the best thermal reaction, puts forward the improvement proposal.