应用正交设计优化煤层注水工艺参数的组合，对地质条件稳定的煤层是实现最佳注水效果的一种较好的方法。但是，对于地质条件不断变化的煤层，采用该方法，其效果不一定能满足注水工程要求。为此，针对地质因素为不稳定状态下的煤层及影响煤层注水的地质因素既有定性变量又有定量变量的特征，提出利用数量化理论与正交设计2种方法确定注水工艺参数的最优组合，并进行了工程试验优化研究。试验结果表明，此法节省注水试验工程量，接近实际工程要求。

To apply the orthogonal design to the optimization of the coal-seam injection technical parameters' combination is a better method that realizes the best effect of injection for the coal-seam with steady geological conditions. But with this method, its effect cannot definitely satisfy the injection engineering requirement for the coal-seam with changing geological conditions. For this reason, in view of the coal-seam with unsteady geological factors and the characteristic that the geological factors have both qualitative and quantitative variables, one method that applies the quantity theory and orthogonal design to determine the optimal combination of injection technical parameters is raised and the engineering experimental study has been made. The experiments show that this method can save the quantity of injection experiment engineering and are approaching to the actual engineering requirement.