An exemplary hot-melting machine (20) includes a worktable (23), a number of carriers (24), a heater (25), at least one cooler (26), and a controller (28). The carriers are located on the worktable and are uniformly spaced apart. Each carrier is configured for holding a workpiece. The heater is configured for heating the workpiece. The cooler is configured for cooling the workpiece. The controller is configured for driving the worktable to rotate, the heater to move down toward and up away from a corresponding one of the carriers, and the at least one cooler to move down toward and up away from another corresponding one of the carriers. At each of successive stages in operation of the hot-melting machine, one of the carriers is aligned with the heater, another one the carriers is aligned with the at least one cooler, and a further one of the carriers is positioned such that a workpiece can be unloaded from the further one of the carriers and another workpiece can be loaded on the further one of the carriers.