Through field plot experiment, we research the influencing factors of cowpea yield and quality after applying boron and molybdenum microelement fertilizer. Results show that the application of boron and molybdenum microelement fertilizer can significantly increase the yield and improve the quality of cowpea. Compared with the control, yield per mu increases by 5.08%-18.86%; N content increases by 4.27%-11.28%; P content increases by 2.13%-13.57%; K content increases by 2.00%-18.48%; crude protein increases by 4.16%-19.94%; vitamin C increases by 2.71%-11.79%; nitrate content decreases by 5%-15%. Besides, it is better to combine boron with molybdenum than to use each of them separately.