Blending several kinds of simple coal with different metamorphism in a special ratio is an important method for coke-making. It can effectively utilize the limited coal resources, expand the range of coals as raw materials for coke-making, improve the quality of coke and increase the economic benefit.People used to determine the blending ratio of coal by experience.The author used a computer-aided technique to obtain the optimized ratio. The core of the model is made up of two parts: linear programming and a set of linear equations. The program was witten in Fortran with man-machine interactive mode. The model has been used in calculating the blending ration in Nov. It is estimated that an economic benefit of $ 110,000 might be obtained.