The seed adsorption disk is an important component of the seed metering device. The differences in size and shape of suction hole on the adsorption disk result in variation of the airflow field formed. A finite element analysis of airflow field for the suction holes of different size and shape was conducted in this paper. The two dimensional simulation of airflow field for different shaped suction hole under the condition of identical bore diameter and air pressure difference reveals that the average airflow velocity inside the different shape of suction holes are the highest one in cylindrical hole and the lowest in tapered hole, the airflow speed at inlet opening of three different suction hole does not vary evidently. Both the result of airflow field two dimensional finite element analysis of different bore diameter suction hole and its proof under the condition of the shape of suction holes and air pressure difference being identical reveal that with the bore diameter being enlarged, the airflow speed inside the suction hole increases in comparison of the airflow speed field for three different suction holes of different bore diameter. To enlarge the bore diameter of suction hole and expand the adsorption surface area of the seed will result in the airflow rate and airflow speed getting higher and the adsorption function on the seed growing stronger.