Abstract: Mars is one of the most important targets of extraterrestrial exploration. Investigation and research on mars surface indicate that liquid water once existed on the mars surface, and water is basis and precondition of life. Therefore, one of today's mars exploration scientific objectives is searching for water both solid and liquid in mars subsurface. For the last 17 years, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) on ESA's Mars Express, and the Shallow Subsurface Radar(SHARAD) on NASA's Mars Reconnaissance Orbiter has probed the mars subsurface at a global scale. Because of operating principle of radar, raw data of subsurface investigation radar should be processed in range and azimuth and correct ionospheric distortion in order to generate radargram. Many scientific achievements have been made in extracting scientific information from radargram. Data processing technology played a indispensable role in mars subsurface investigation, which shows great representativeness and reference value. We described the investigation and research about Martian subsurface with radar in this overview, introduced data processing technology using in Mars subsurface investigation, and presented part of findings of MARSIS and SHARAD. We also introduced several future Martian subsurface radars in this paper.