The impact of (N+1)×1 coupler pump arm numbers on the pump coupling efficiency was numerically studied firstly. It is shown that pump coupling efficiency decreases with more pump arms built on the coupler, yet in a slightly decreasing manner. According to the simulation results, side-pumped (1+1)×1 and (2+1)×1 couplers were made. The total output power of the (2+1)×1 coupler is about 681 W, almost two times that of the (1+1)×1 coupler, enhancing the pump light injection capacity of the fiber laser system significantly.