In order to meet the goal of green and low-carbon steel smelting, large-scale pellets production has become an inevitable demand. Due to the thick material layer of the straight grate and the static pellets during the roasting process, in order to ensure the quality of the finished pellets, the uniform distribution of fresh pellets is particularly important. After the distribution principle and distribution process equipment parameters of the straight grate are studied, the reasonable distribution method is determined. The results show that the distribution of the shuttle and the swing head belt conveyor has such problems as numbers of fresh pellets falling and the uneven distribution. The distribution of reciprocating distributor can reduce the number of fresh pellets falling, and can realize one-way distribution and fast reversing, so as to ensure uniform distribution. Through the parameter calculation, it is concluded that the reasonable distribution method of the 504 m² belt roaster is reciprocating distributor + wide belt conveyor distribution, the moving speed of the unloading trolley and the running speed of the belt should be controlled at 0.65 m/s, and the running speed of the wide belt conveyor should be controlled at 0.12 m/s. The production practice shows that under this distribution method, the distribution trajectory is neat, the material surface of the trolley is smooth, and the strength of the finished pellets is uniform, which achieves the expected research goal.