Abstract: It is of practical need and significance to study the technology of the in-situ resource utilization, while looking into the future missions such as Mars sampling & return mission, the manned Mars exploration and the Mars base construction. The recorded Mars explorations show that the water resources exist in the ice caps at the south and north poles of Mars, as well as in the Martian soil and atmosphere. In this paper, a method to extract the water from the surface soil of the Mars is proposed, which uses the solar radiation to ensure the sublimation of the water ice and the water vapor solidification into the frost. The principle design of the device is given. The sublimation time of the ice in the soil with a certain thickness is calculated by the finite difference method. The feasibility is then analyzed according to the calculation results.