The oil pump power loss in transmission efficiency in automatic transmission is an important factor. Because, the pump supply rate at high engine speeds is much greater than the Transmission needs. This paper proposes two-oil pumping system minimizing of flow rate and power demand in the automatic Transmission. In addition, the electric oil pump control method of optimization is proposed. The effect of pumping system was confirmed by experiment. As a result of the simulation, two-oil pumping system is expected to improve both fuel efficiency and acceleration performance.