Abstract: An optimization method for a directional preparation technique and efficient use of semi-coke for blast furnace injection. Firstly, the volatile and the ash content of target semi-coke are preset, and then the volatile and the ash removal percentages of a raw coal are calculated; after ash removal, several sets of dry distillation carbonization temperatures and carbonization times are obtained according to the volatile removal percentage, and the relationships between a combustion rate, abrasiveness, explosiveness and jet flow property and the carbonization temperature are respectively established to obtain the optimal actual carbonization temperature; and semi-coke for blast furnace injection is obtained at an actual carbonization temperature.