Online maintenance low-temperature ball valve and tool thereof

The invention relates to the technical field of valves, and particularly relates to an online maintenance low-temperature ball valve. The online maintenance low-temperature ball valve comprises a valve body, a valve element, valve seat assemblies and a valve deck, wherein the valve body comprises an axial channel used for medium circulation and a radial channel perpendicular to the axial channel;the valve seat assemblies are symmetrically arranged in the axial channel and comprise elastic assemblies and axial sealing assemblies; each axial sealing assembly comprises a valve seat supporting ring; the valve seat supporting ring makes contact with the spherical surface of the valve element; the face, making contact with the valve element, of the valve seat supporting ring is an arc face; thearc face is provided with a sealing groove used for fixing a sealing ring, the valve seat supporting ring is movably arranged along the axial channel; the end of the valve seat supporting ring protrudes out of one side wall o