In this paper, aiming at the current development of domestic agricultural production, introduced a variable fertilizer controller which suits for a domestic food-producing areas to promote output. The variable rate fertilization controller combined with the current Chinese made fertilizer equipment; mechanism of metering system for the applicator uses a flute wheel. The amount of fertilizer is determined by the rotation speed of flute wheel. The use of the control system can be inconsistent in soil fertility, pre-division of plots with different fertilizer way through the process of moving the driver automatically adjusts the amount of fertilizer direction buttons to precision variable fertilization. Papers on the electronic structure of the controller and software design in detail. In addition, we have examined the performance of this new product in the field by using different fertilizer and requirement. The results reveal that semi-automatic controller work well by controlling the quantity of fertilizer precisely. Specifically, coefficient of variation of fertilizing is controlled to be less than 5%. That means this new type semi-automatic controller worth developing in further.