The utility model provides a steel belt butt joint machine which comprises at least two sets of end covers, a base and a countersunk bolt. The operation face of each end face is provided with a through groove and the operation face of the base is provided with two through grooves, so that after the end covers are buckled with the base, two rectangular through holes are formed. When break belts are in butt joint, the steel belts are hammered on a reinforced square steel rod through a hammer, after the belt heads and the belt tails are put into the through holes, the countersunk bolt is properly fastened, tensile force is respectively exerted on the belt heads and the belt tails, after the steel belts are tightened, the countersunk bolt is fastened, the tensile force is exerted, and the belt heads and the belt tails are tightly clamped on the inner walls of the through holes by the reinforced square steel rod. According to the steel belt butt joint machine, the height of the butt joint machine can be reduced, the butt joint machine can smoothly pass through the narrow zones of sealing roller portions and the like, and the accident of belt breakage is avoided; single-layer extrusion molding is adopted by the steel belts, the labor intensity is relieved, the operation time can be shortened, and the operation rate can be increased by over 30%. The friction resistance is increased through the external force, so that the fastening effect is guaranteed, the steel belt connection successful rate and the machine set operation rate are increased, and the production cost is reduced.