The thermal bridge effect of vacuum insulation board (VIP) is numerically analyzed, and the concept of edge linear heat transfer rate is introduced as a reference quantity to measure the size of the thermal bridge effect. Based on the steady-state heat transfer boundary conditions, a heat flow transfer model is established, and the influencing factors are analyzed and calculated.The research results show that the main influencing factors are the thermal conductivity and thickness of the core material, the thermal conductivity and thickness of the air-insulating structure, the thermal conductivity and thickness of the filling medium between the VIP, and the specifications of the VIP.Among them, the edge linear heat transfer rate increases with the increase of the thermal conductivity and thickness of the core material, the thermal conductivity and thickness of the air-insulating structure decrease, the thermal conductivity and thickness of the filling medium are smaller, and the VIP specifications show a decreasing trend.Combining the influencing factors, the article proposes to reduce the thickness and thermal conductivity of the air-insulating film, reduce the thermal conductivity of the core material and the filling medium, appropriately increase the specifications of the VIP, improve the installation process and other optimization measures to reduce the thermal bridge effect.