Abstract: In the Solar system, there are many astronomical objects owning the magnetosphere structure generated by the interaction between their intrinsic magnetic field and Solar wind, including Mercury, Earth, Jupiter, Saturn, Uranus, Neptune and some of their satellites. Heliosphere is the Sun’s magnetosphere, which is filled with Solar wind and surrounded by the interstellar medium. According to the data obtained by the existing detectors, the interaction between the Solar wind and the interstellar medium, the distribution of energy neutral atoms and the relative spatial density changes of picked-up particles, the formation mechanism of abnormal cosmic rays, and possible changes in the shape of the heliosphere are introduced. The marginal exploration plan of China’s Solar system exploration mission is given. Two detectors in opposite directions are designed. One will fly towards the nose tip of the heliosphere to conduct comprehensive exploration of the marginal Solar system and its adjacent space; and the other will fly in the opposite direction to fill the gap at the tail boundary of the spherical layer. The knowledge of the space environment of the heliosphere can provide reference for the design of the probe.