In order to study the characteristics of temperature distribution in a forced convection oven, and to optimize the uniformity of the temperature field inside the oven, the experimental and numerical simulation was carried out. The temperature distribution of each layer was measured by 3×3 distributed resistance points (Pt), and the temperature uniformity was measured and analyzed. The Computational Fluid Dynamics (CFD) method is used to simulate the temperature field inside the oven, considering the heat conduction, convection and radiation. The accuracy of the numerical simulation method is verified by the experimental results. Based on the experimental and simulation results, the reasons for the non-uniform temperature field of the original structure of the oven are revealed and analyzed. The uniformity of the temperature field in the oven is improved by adding the guide vane structure, adjusting the position of the heating tube, improving the heating tube and improving the baffle.