During the Earth-Mars transfer and circum-Mars flight of TianWen-1 Obiter, optical/electro-optical measurement sensitizers are used to measure reference target objects such as the Sun, stars, Mars, etc., combined with the natural kinematic relationship of the reference target objects, to realize the precise determination of the inertial attitude and flight trajectory of the Obiter, and to provide a reliable and effective input for the attitude-pointing control of the whole process of the flight. The optical navigation sensitive device acquired the Earth-Moon conjunction photo at a distance of 1.2 million kilometers from the Earth, and carried out the verification of optical autonomous navigation for approaching Mars at a distance of 3 million kilometers from the planet; and the infrared navigation sensors carried out the verification of autonomous navigation technology based on the local edge-of-Mars image in the large elliptical orbit of the circum-Mars flight. At the same time, a separation measurement sensor was configured, which was separated from the detector at an opportune time during the Earth-Mars transfer and the circling of Mars, and the detector’s self-timer image during the Earth-Mars transfer flight and the circler’s self-timer image during the circling of Mars flight with Mars as the background were obtained in the free-floating state.