A geophone with a magnetic-liquid sealed gas spring consists of external binding posts, an upper cover, an upper sealing ring, a casing, a movable ring frame, a coil, a permanent magnet, a lower magnetic shoe, lower magnetic liquid, the gas spring, a lower cover, a lower sealing ring, a lower framework cover, an upper magnetic shoe, upper magnetic liquid, an inner binding post, a transverse soft connecting spring, an upper framework cover, inner upper binding posts and upper soft connecting springs. The casing, the lower cover and the upper cover are integrally packaged via the upper sealing ring and the lower sealing ring, the movable ring framework, the upper framework and the lower framework are integrally packaged between the casing and the magnetic shoes of the magnet to form a framework combination, a certain gap is formed between the framework combination and the upper cover and the lower cover as well as between the magnetic shoes and is sealed by the magnetic liquid, and the gas spring formed by nitrogen gas is sealed in the gap. Compared with other geophones, the geophone adopts the gas spring sealed by the magnetic liquid to support a movable ring of a detector, and accordingly, elastic coefficient of the detector increases along with increase of displacement, and purposes of the high-performance detector are achieved.