The invention discloses a precision seed metering device of seeds with middle and large grain diameters. Seed taking principles of pneumatic seed metering devices and mechanical seed metering devicesare combined, and a seed carrying component and a seed metering component are designed, wherein negative pressure and indent holes are combined to conduct seed taking. The precision seed metering device includes a seed metering device shell, a seed removing device, a seed storage device and a shaft; the seed metering device shell includes an end cover, a cover plate, a belt and an external fixingplate; the shaft is mounted on the external fixing plate; the seed removing device is located at the inner side of the end cover of the seed metering device, and the seed storage device is composed ofa seed metering disc, an indent hole sliding block mechanism and a cam-like mechanism. The precision seed metering device can adapt to the appearance requirements of the seeds; in a seed taking stage, the seeds enter the indent holes through negative pressure and self-gravity, then, superfluous seeds are brushed back to a seed chamber through the seed removing device and enter a seed carrying area, the seeds are still subjected to an adsorption effect, indent hole sliding blocks are closed so that the seeds can be more stable in a seed carrying process, a dual seed protection effect is achieved, and finally, the seeds pass through a secondary seed putting area to be put into seed holes. Overall, by adopting the precision seed metering device, power consumption can be reduced, the seed carrying rate is increased, the seed damage rate is reduced, and the sowing qualification rate of the precision seed metering device is increased.