Abstract: Abstract: Because of the covering of a large amount of root and straw after no-tillage sowing, when doing inter-tillage and topdressing, it will cause the rate of seedling injury to increase and affect crop yield, and meanwhile, due to no fertilizer application before no-tillage sowing, so it is very important to supply sufficient fertilizer to meet different crops' nutrient requirements on the growth duration. Relevant research points out that, when the layer spacing and ratio between based fertilizer and seed fertilizer are 6 cm and 3:7 for wheat, the fertilizer can guarantee crop's nutrient requirements in different stages, but for soybean, it is 4-8 cm and 1:2, and other crops are also different. There are many research reports about layered fertilization ditcher in and abroad, but there are few researches on fertilizer allocation device. So, it is very important to design a new fertilizer allocation device with adjustable ratio. The application of prototype simulation technology of granular materials has become simple and easy with the increase of computer operation speed and the introduction of EDEM, and meanwhile, it can shorten the time of research and development cycle and reduce the costs. A new fertilizer allocation device with adjustable ratio, which consists of bevelled tongue outer groove-wheel fertilizer feeder, fertilizer uniform distribution device and fertilizer ratio-adjusting device, has been designed, and it has the function of separating the fertilizer in different layers in adjustable setting proportion, and meanwhile, the main parameters of key parts have been made by theory analysis. In order to enhance the accuracy and stability of fertilizer allocation device with adjustable ratio and analyze the influence on working performance when structure parameters of fertilizer uniform allocation device change, at first, the discrete element simulation model of fertilizer allocation device with adjustable ratio is built by using EDEM and the working process is simulated. The fertilizer particles' space distribution in entrance and exit of fertilizer uniform distribution device indicates the device can enhance the uniformity of particles' space distribution and realize its function. The bar diameter and the divided number are selected as test factors, the qualified index and the wave index were selected as index, and the two-factor and three-level orthogonal parameter optimization test is conducted. The results indicate that, for the 2 test indices, the divided number is very significant (P<0.01) and the bar diameter is significant (P<0.05); the qualified index decreases with the divided number and the bar diameter increasing, and the wave index decreases with the divided number increasing and the bar diameter decreasing; the qualified index is 0.903, the wave index is 68.6, and the fertilizer uniformity distribution device has the best working performance when the bar diameter is 4 mm and the divided number is 16. Second, in order to verify the simulation test results and prove the feasibility of parameter optimization of fertilizer uniform distribution device using simulation test method, different fertilizer uniform distribution devices have been built and the verification test has been carried out with the same test method. The verification test has the same results with the simulation, but in the verification test, the qualified index is 0.928 and the wave index is 78.0 when the optimized structure parameters are also 4 mm bar diameter and divided number of 16. The simulation test and verification test have the same response of factors, and the simulation parameter optimization has been validated which show the simulation test method is feasible. The result has a certain reference value for the research of fertilizer allocation device.