The embodiment of the invention provides an extension-type device and a tire mold and relates to the technical field of the tire molds. The extension-type device comprises a supporting component, a driving component and a moving component located between the supporting component and the driving component, wherein the moving component comprises a plurality of first moving blocks and a plurality ofsecond moving blocks, the plurality of first moving blocks and the plurality of second moving blocks are distributed around a central axis, the first moving blocks and the second moving blocks are arranged alternately in sequence, the first moving blocks are slidably connected with the supporting component and have the tendency to move close to the central axis, the second moving blocks are slidably connected with the supporting component and have the tendency to move close to the central axis and the driving component, the first moving blocks are provided with first contact surfaces, and thesecond moving blocks are provided with second contact surfaces used for being in fit with the first contact surfaces of the adjacent first moving blocks.