In response to the harsh sea environment, the structure system of target devices with unmanned is researched. By establishing a mathematical model of heat generation for the target devices, the optimal heat generation structure of top-down tooth radiator is obtained. Therefore, a new double-layer convolute mode seal structure and method is proposed based on height difference. The mechanism and solution of respiration effect is analyzed. Anti-random wave load and anti-impact of the buffer and vibration platform are developed. The reliability and accuracy of the target devices are tesed through seal and buffer vibration experiments. These results provide powerful technical support and guarantee for the unmanned target devices of the harsh sea environment, while the level of target devices combat training is improved.