A process for preparing solar-grade N-type monocrystalline is disclosed. The process includes (1) adding a silicon raw material into a quartz crucible put into a monocrystalline furnace, adding an N type master alloy and gallium to the middle position of the silicon raw material; (2) closing the monocrystalline furnace, vacuumizing the furnace to detect leakage, heating the furnace for a melting purpose, adding the silicon raw material with a repeated feeder and heating the furnace for a melting purpose; (3) cooling the furnace, stabilizing the temperature, finding out power, melting seed crystal, seeding, crowning, shouldering, bodying and tailing to obtain a first monocrystalline rod, pulling the monocrystalline rod to an auxiliary chamber of the monocrystalline furnace to be cooled, andmaintaining the temperature of the residual solution in the monocrystalline furnace; (4) taking the monocrystalline rod out after the monocrystalline rod is cooled and weighing the monocrystalline rod; (5) adding a material for repeated addition into the repeated feeder, and adding an N type master alloy and gallium to the middle position of the silicon raw material; and (6) heating the furnace for a melting purpose, cooling and stabilizing the furnace, finding out power, melting seed crystal, seeding, crowning, shouldering, bodying, tailing, and cooling the product to obtain a second monocrystalline rod. A proper amount of the gallium is added in the initial material addition to neutralize phosphorus better and to effectively improve the degree of centralization of the specific resistance of the N-type monocrystalline, thus increasing the percent of pass of solar resistance.