Weak caking coal is a kind of bituminous coal with weak caking property, and its metamorphic degree varies from low to medium. When heated, less colloids can be produced. When coking alone, some small coke blocks with poor strength will be formed. In order to make rational use of coal resources and solve the problem of coal scarcity, by continuously optimizing the coal blending scheme, an appropriate amount of weakly caking coal is added in the coal blending process to reduce a certain amount of main coking coal. At the same time, the influence of weak caking coal on the conventional caking performance index of coal blending was studied. By comparing the measured values and predicted values of the bonding performance index, the relationship between the two is discussed, which provides a theoretical basis for predicting the bonding performance index of the blended coal after blending with weakly caking coal.