In order to treat the small town sewage wastewater with high efficiency, energy saving and low power consumption, a combined coagulation cloth media filtration-anaerobic filter／trickling filter system was established at experimental condition. Via the experimental optimization of equipments and materials, the optimal operation parameters of each part, especially the nitrogen removal ability during the start-up of the trickling filter had been investigated. Experimental results showed that at 1 mL／L fly ash coagulant dosage, 54％ removal of COD_cr and 81％ of TP would be removed by the combined system. The optimal hydraulic loading was 15 L／d and the optimal reflux ratio was 150％, which would guarantee the effluent ammonia, COD_cr, TP reach A standard.