In order to improve the guiding migration performance of pickup finger precision seed metering device, the steady migratory mechanism of guiding-seed system was studied. The kinematics and dynamics models of guiding-seed and dropping-seed processes were established based on its working principle. The influences of various factors on dropping trajectory and migration stability were analyzed. The quadratic general rotary unitized design was carried out by taking the rotational speed of seed meter and tilt angle as experiment factors, and the seeding qualified index and variation coefficient as experiment indexes. Based on experimental data, a mathematical model was built by using the Design—Expert 6.0.10 software, and the experiment factors were optimized, the best combination was achieved. On this basis, a kind of dropping trajectory measuring test platform was designed and built based on the theory of mirror reflection. And then the three-dimensional space velocities of the falling corn were measured and analyzed by high-speed photography and target tracking technology. The single factor tests for factors, including rotational speed and tilt angle, were carried out and the corresponding regression equations were obtained by analysis. Experimental results showed that when the rotational speed was between 15r/min and 45r/min and the tilt angle was 0°, the horizontal displacements of trajectories of frontal and profile dropping seed were increased with the increase of rotational speed and the variation coefficient of seeding was decreased with the increase of rotational speed. As the rotational speed was greater than 35r/min, the trajectories and landing positions of corn grains were gradually discrete and the variation coefficient of seeding was significantly increased, and its horizontal displacements of frontal trajectory were stabilized within the range of 12.9~14.3mm, the horizontal displacements of profile trajectory were stabilized within the range of 3.7~4.8mm, and the average variation coefficient was 15.13%. The dropping seed angle was decreased with the increase of tilt angle at rotational speed of 30r/min and tilt angle of -12°~12°. The results can provide guidance and direction for the research of mechanical precision seed metering device and its seed tube.