The invention relates to a ship unloader metering mode control method. The method comprises the following steps: S1) detecting whether a system is normal and starting a metering mode; S2) carrying out grab hopper material taking, and after receiving a material discharging instruction, discharging material to a measuring hopper; S3) weighing rough weight of the material in real time through a metering device, wherein the metering device carries out material rough weight weighing after the instrument value of the metering device is stable; S4) opening a gate of the measuring hopper and discharging the material to a discharge hopper, and after discharging is finished, closing the gate of the measuring hopper; S5) weighing tare weight of the material through the metering device, wherein the metering device carries out material tare weight weighing after the instrument value of the metering device is stable; S6) calculating the weight of the material; and S7) repeating the steps S2)-S6). The reasonable and high-efficiency ship unloader metering mode control method guarantees metering precision of a ship unloader and improves discharging efficiency of the ship unloader, and guarantees transaction fairness and enterprise production operation efficiency.