In order to solve the problem of fresh water demand for ocean survival on ships, a light distillation seawater desalination device for life rafts for ocean survival is proposed. The water production of the device under different degrees, seasons and weather conditions is analyzed by combining theory with experiment. It can be concluded that the total daily solar radiation and the total efficiency of the device can be used to estimate the water production of the light distillation desalination device. By employing the high light absorbing material “Dark Metallic Nano-materials”, the total efficiency of the device can reach 47.58%, which is 58.60% higher than that of ordinary disk solar distillers. The proposal of the light distillation seawater desalination device, as well as the calculation, analysis and actual measurement of its water production, can provide a reference for the equipment of life raft desalination device on oceangoing ships.