The invention discloses a production process of a rubber diaphragm of an automobile brake chamber. The production process concretely comprises the following steps of: preparing materials; placing a lower-layer rubber brick into a lower model cavity, covering canvas and positioning the canvas by using a compression ring; closing a first upper die, and partially vulcanizing the lower-layer rubber brick; placing an upper-layer rubber brick on the canvas in the lower model cavity; closing a second upper die, and integrally vulcanizing an upper rubber layer and a lower rubber layer of the diaphragm; and taking the product out, and trimming the product to obtain a finished product. The upper-layer rubber brick and the lower-layer rubber brick are respectively made of rubber materials with same formula system and different vulcanization speeds; the time T for sufficient vulcanization of the lower-layer rubber materials is equal to the sum of the time for partial vulcanization and the time for integral vulcanization; and the time for the integral vulcanization is the time for sufficient vulcanization of the upper-layer rubber material. The invention effectively solves the problem of over vulcanization of the lower-layer rubber of the diaphragm in the production process and overcomes the defect that aging occurs in the lower-layer rubber anterior to the upper-layer rubber to result in scrapping of the diaphragm, thereby prolonging the service life of the diaphragm.