The invention discloses an automobile driving axle with a decelerating effect. The automobile driving axle comprises an axle housing. An embedded groove is formed in the inner cavity of the axle housing, a driving speed change mechanism is fixed at the center of the inner cavity of the embedded groove, and a left half axle and a right half axle are connected with the left side and the right side of the driving speed change mechanism correspondingly; a first reduction gear and a second reduction gear are arranged on the left half axle and the right half axle correspondingly, the first reduction gear and the second reduction gear are both fixed in the embedded groove, a left wheel hub and a right wheel hub are connected with the other ends of the left half axle and the right half axle correspondingly, and the left wheel hub and the right wheel hub are both arranged on the outer side of the axle housing; and an air compressor is fixedly installed in the inner cavity of the embedded groove, a driving hole is formed in the bottom of the center of the axle housing, a transmission shaft is connected with the bottom of the driving speed change mechanism, and the other end of the transmission shaft penetrates through the driving hole and is arranged on the lower side of the outer wall of the axle housing. According to the automobile driving axle with the decelerating effect, the structure is simple, and the reduction gears enable the automobile driving axle to achieve a decelerating effect.