The invention provides a heat-shrinkable tube machine for assembling stepped terminals at two ends of a wire material. The machine comprises a worktable and an electric control device. The worktable is provided with an incoming wire straightening station, a wire cutting station, a first pre-peeling station, a first wire transfer station, a first positioning and peeling station, a first terminal feeding station, a first terminal crimping station, a wire reversing station, a tube sleeving station, a heat shrinking station, a wire head inspection station, a second pre-peeling station, a second wire transfer station, a second positioning and peeling station, a second terminal feeding station, a second terminal crimping station and a discharging station from the front to back. The machine integrates the functions of automatic feeding, stripping, double-head terminal assembly, tube sleeving and heat shrinking, one worker can supervise multiple devices, the labor intensity is reduced, the production efficiency is effectively improved, the reduction of product coat is helped, and the product consistency and quality are improved.