In order to improve the quality of pellet and reduce the "black core" structure of pelletizing, and to determine a reasonable process system and ore proportioning scheme, the imported magnetite concentrates A, B, C and D are used as raw materials in this paper, and 50% D ore + other concentrates are adopted for the ore proportioning scheme study according to the basic characteristics of single ore pellets, and grate-kiln process parameters is optimized. The results show that: in the concentrate ore proportioning scheme, the scheme of 50% D ore + 40% C ore + 10% B ore is more reasonable; the temperature order that affects the strength of preheating pelletizing is preheating stage Ⅱ temperature > extraction air drying temperature > preheating stage Ⅰ temperature > exhaust drying temperature. Under the temperature of the exhaust drying section, the preheating stage Ⅰ and Ⅱ of 250,300,720 and 990 ℃ respectively, the preheating ball can be fully oxidized, and the pelletizing strength at the outlet of the grate can reach 1 105 N/P; when the roasting temperature is 1 270 ℃ and the roasts time is 25 min, the strength of the pelletizing at the outlet of the kiln can reach 3 710 N/P, and the pellets can be fully oxidized. The conclusion can provide a theoretical and technical support to improve the reduction property of pellet and play a role of pellet as a concentrate in the smelting process of blast furnace.