Abstract: In order to further understand the effect of different chemical control agents in soybean and maize complex planting and increase the economic benefit of soybean and maize complex planting, three chemical control agents, Yuhuangjin, Chlormequat chloride and invigorin were tested with water. After the completion of the experiment, the statistical results of the whole growth cycle of maize and soybean showed that the short and strong grain had a great influence on the control of maize plant height, which was suitable for large-scale popularization.