In order to treat municipal wastewater not included in the pipe network, silica sand loading coagulation process was adopted. The effects of particle size and dosage of silica sand on the treatment efficiency were investigated, the removal characteristics of dissolved organic matters(DOM)were analyzed, and the coagulation mechanism was discussed. The results show that when the particle size and dosage of silica sand are 200 mesh and 1. 0 mg/L, respectively, the removal rates of turbidity and COD by silica sand loading coagulation are 97. 55% and 59. 2%, respectively, which are better than the conventional coagulation. The aromatic, conjugated double bond and hydrophobic organic matter can be obviously removed by silica sand loading coagulation, which mainly promotes the reduction of humus. Through bridging, silica sand increases the density of flocs, and then significantly improves the settlement performance and strength of flocs. The settling property, strength and re stability of flocs increase with the decrease of silica sand particle size.