The embodiment of the invention discloses a bridge arm of a motor driving circuit and a control method thereof, and relates to the technical field of electrical equipment and electrical engineering. According to the invention, the reverse recovery problem of the MOSFET diode of a motor bridge arm in the large-current condition can be inhibited, and the loss of a motor drive circuit is reduced. Meanwhile, the system efficiency is improved. The bridge arm includes a bridge arm switch tube, a bridge arm optimized switch tube, a reversed series connection switch tube, a reversed parallel connection switch tube, a driver and a delay link. The reversed series connection switch tube can be in series connection with an upper bridge arm switch tube and can also be in parallel connection with a lower bridge arm switch tube. Meanwhile, the switching loss of both the upper bridge arm and the lower bridge arm is reduced at the same time through two switch tubes reversely connected in series with each other, so that the loss-reducing optimization is realized. The reversed parallel connection switch tube is connected in parallel with the bridge arm of the reversed series connection switch tube. The technical scheme of the invention is applied to the reverse recovery suppression of motor bridge arms.