Shenmu coals as low rank coal are difficult to prepare for Coal Water Slurry (CWS). The maximum slurry concentration of Shenmu CWS is lower than 60%, which is not available for practical application. Coal blending is a simple operation and low cost method to improve the slurry ability of low rank coal. Two different kinds of anthracite and bituminous coal samples were blended in Shenmu coal to study the effect on the preparation of CWS, respectively. The results showed that the maximum solid concentration of CWS increased as the proportion of high rank coal rise. And the viscosity of CWS is dropped at the same concentration. Different coals blending have different effects on the elevation of slurry ability for Shenmu coal. The raw coal with best slurry ability is not always the most suitable for blending in low rank coal. HuanNan bituminous coal is the best choice for blending in Shenmu coal. The maximum solid concentration of CWS can be increased by 6% when the proportion of HuanNan coal reached to 70%.