In view of the field experiment of deep fertilization in paddy field affected by various factors such as short planting season and unstable operation performance, the traditional indoor soil tank could not carry out the experiment of deep fertilization in paddy field by air delivery, a test bench was designed independently to detect the parameters of deep fertilization and fertilizer discharge in paddy field by air delivery. The test bed was mainly composed of the mechanical part, the control part, the fertilization by wind and the software part. The automatic control technology, multi-sensor technology and hydraulic transmission technology were adopted comprehensively to simulate the working conditions of paddy fields, realize the real-time collection and display of wind pressure, wind speed and other parameters during the process of wind feeding and discharging fertilizer, and flexibly control the speed and turn off frequency of the fertilizer discharging wheel. The performance verification test showed that the traveling speed of the test bed can be adjusted within 0~1.62m/s with an error of 1.5%. The fan provides air velocity of 0~30m/s to meet the demand of air feeding and discharging fertilizer. The maximum coefficient of variation was 5.79%, which met the requirements of fertilization. Based on the test-bed, the results showed that the influencing factors of fertilizer uniformity, fertilizer amount variation coefficient were as follows: fertilizer wheel speed, trolley forward speed, wind speed. The test-bed can test the parameters of the side deep fertilizer in the laboratory environment. The research and development cycle of key components of side deep fertilization in paddy field was shortened. This study laid a foundation for the realization of intelligent control of side deep fertilization in paddy field.