The invention provides an isolation type seed-metering device and an application method thereof, aiming at the problem in the prior art that a seed box is communicated with a seed sowing mechanism sothat the seed sowing precision is influenced. The isolation type seed-metering device comprises a vibration seed box for storing seeds, a movable seed leakage assembly arranged just below the vibration seed box and a direction dividing chamber which is arranged just below the movable seed leakage assembly and is used for discharging the seeds, wherein a plurality of leakage holes for discharging the seeds are formed in the bottom of the vibration seed box; the isolation type seed-metering device is characterized in that the movable seed leakage assembly comprises a driving part, a driving transmission roller driven by the driving part, a driven transmission roller, an isolation conveyor belt of the driving transmission roller and the driven transmission roller, and a seed discharging thickplate arranged between the driving transmission roller and the driven transmission roller. The isolation type seed-metering device provided by the invention is simple in structure; a seed sowing partand the vibration seed box are isolated through the isolation conveyor belt, so that the seed sowing precision is improved.