Using bean Jiuyueqing as a test material, a comparative cultivation experiment was conducted in a plastic greenhouse. The biological characteristics and yield structure of bean Jiuyueqing were comprehensively analyzed,and the optimum height of bean topping was 1.5 m. The results showed that the topping had little effect on the stem thickness of the bean Jiuyueqing. When the topping height is 1.5 m, the bean can be listed about 13 days earlier,and the maximum leaf area index is 6.42. It is hoped that this experiment will further clarify the topping height of kidney beans, and at the same time provide theoretical conditions for improving the mechanism of topping beans.