The 3QXZ-6 seed corn detasseling machine was designed to improve the mechanical level during corn cultivation. The machine was consisted of profiling mechanism, hydraulic driving system and plantprofiling controlled system. The profiling mechanism was structured as a parallelogram. Roller was motivated by the loadsensing hydraulic system, and height adjustment was manipulated by cylinder, which was driven through proportional control hydraulic system. In a set distance, if the lower photoelectric signal is continuously lost, it indicates the plant is short, and if the upper photoelectric signal is continuously received, it indicates the plant is relatively tall. This is how the plant height profiling is fuzzily controlled. The test on synchronization performance of roller rotation speed, response time of controlling system, and hydraulic cylinder speed shows that when the engine rotation speed is around 2300r/min, the maximum deviation ratio of roller rotation speed is 4.4%, synchronization tolerance rate is less than 3%, responding time is 0.04s, cylinder liftingup speed is 0.21m/s, and droppingdown speed is 0.27m/s. Based on the data collected from experiment, a function was built by using control signal t as variable and vertical movement of tassel removal component. Field experiment proves that the 3QXZ-6 seed corn detasseling machine is reliable and highly efficient. It sufficiently meets the agronomy detassling requirement with a detasseling ratio 87.7% averagely.