A long tube plastic film bag for garbage cans and a packaging method thereof, and a packaging mold are provided. The long tube plastic film bag includes a long tube plastic film bag body and an outer packaging. The outer packaging is a film tube material. The film tube material includes a first opening and a second opening. One annular first groove is formed between the first opening and the second opening. An end of the long tube plastic film bag body is an open end, and another end is a sealed end. The long tube plastic film bag body is gathered toward the open end and stored in the first groove. The sealed end of the long tube plastic film bag body is extended out of the first groove of the film tube material.