Abstract: The vapor chamber heat spreader cooling technology is employed in this paper to solve the heat dissipation problem in the digital plug-in modules with high heat consumption. To verify the heat dissipation capacity of this technology, both simulation and experimental studies have been conducted. The results demonstrate that when the coolant supply temperature is 65 ℃, the ambient temperature is 30 ℃, the coolant flow rate is 0.6 L/min and the heat consumption of the single board is 200 W, the operation temperatures at measurement points are not higher than 80 ℃. Under all work conditions, the maximum temperature difference on the surface of vapor chamber heat spreader is not higher than 7 ℃. The maximum heat transfer capacity is about 330 W in the horizontal orientation and 360 W in the vertical orientation, when the surface temperature of the vapor chamber heat spreader is not higher than 100 ℃. The equivalent thermal conductivity of the surface of vapor chamber heat spreader is approximately 3 000 W/(m·K), which is 15 times that of 6063 aluminum alloy, roughly 8 times that of oxygen-free copper and nearly 5 times that of diamond/copper composites. In addition, shock and vibration experiments confirm that the heat spreader meets the requirements of GJB 150A. This technology can significantly reduce the operation temperature of the plug-in modules and no fluid connector is required, so the heat spreader has no risk of leakage and its lightweight design can be achieved. Therefore, it can be widely used in heat dissipation of the digital plug-in modules with high heat consumption or in scenarios with strict requirements for weight and reliability.