The invention relates to a toothed belt high-frequency heat-sealing machine and a heat sealing method; the heat-sealing machine comprises a machine frame, a high-frequency generator, a control box and a high-frequency electrode; a circular toothed belt is sheathed on a front gearing wheel and a back gearing wheel and a support table between the two gearing wheels and the gearing wheels drive the circular toothed belt to move by a gear drive mechanism. The invention has the advantages that firstly, the welding lines which need thermal sealing and spicing can be heat-sealed and spliced conveniently into various shapes such as arc, round, curve, and the like and realize the manufacturing of various flat products and solid hollow products; secondly, by taking the circular toothed belt as the working table, the occupied field area is small and the two plastic cloth which need to be heat-sealed can be spiced continuously; thirdly, by adopting the circular toothed belt as the electrode whichis produced by high-frequency electric field, not only the function of toothed belt transportation can be provided, but also a high-frequency electromagnetic field can be formed with the high-frequency electrode in a high-frequency generator; therefore, the two plastic cloth which need to be heat sealed and spiced can be ensured to be heat-sealed into a whole firmly.