The invention discloses an efficient and energy-saving shrink machine for heat shrink tubes on an assembly line. The efficient and energy-saving shrink machine comprises a trapezoidal support. Rollers are mounted on the upper side of the trapezoidal support, rotary shafts are respectively arranged on the left side and the right side of the trapezoidal support and are connected with a motor, a conveyor belt is connected onto the rotary shafts and the rollers, heat shrink tube support strips are uniformly distributed on the conveyor belt, two rows of harness ring clamp grooves are formed in the conveyor belt and are respectively close to the edges of two sides of the conveyor belt, the harness ring clamp grooves on each row are positioned on the same straight line, and a heat-insulation plate is fixed to the upper side of the trapezoidal support and is positioned on the lower surface of the conveyor belt. The efficient and energy-saving shrink machine has the advantages that the work efficiency can be improved by the aid of an assembly line form, the heating time and heating temperatures can be effectively controlled, and the high-requirement shrinking purpose can be achieved; the purpose of saving energy can be achieved by means of recycling hot air, workers can be separated from heating locations and can be protected against heating of the shrink tubes, irritation of other insulating gas and effects of the high temperatures, accordingly, the physical health of the workers can be protected, and occupational diseases can be reduced.