The invention provides a rubber sole injection mold and an injection molding method. The injection mold comprises an upper mold body, a middle mold body and a lower mold body which are sequentially combined. A shoe tree capable of being sleeved with an upper is arranged on the lower mold body. An up-down-through upper peripheral banding hole is formed in the middle mold body. A sole forming groove and injection holes communicating with the sole forming groove are formed in the upper mold body. During mold combination, the upper periphery is banded by the upper peripheral banding hole and the shoe tree, a closed sole mold cavity is defined by the middle mold body, the shoe tree, the upper periphery and the sole forming groove, one-time injection combination of the rubber sole and the sewed upper can be achieved by means of the rubber sole injection mold, and the fit step of the rubber sole and the upper is omitted, so that the labor cost is saved, and the production efficiency is improved.