Refuse derived fuel（RDF）was dechlorinated and modified by microwave low temperature pyrolysis technology. The effects of final dechlorination temperature, heating rate and microwave absorbent on the dechlorination ratio and the combustion performance of RDF were explored. The dechlorination ratio was increased with the increasing of the final dechlorination temperature. When the temperature rose from 220℃ to 300℃, the dechlorination ratio increased from 16% to about 65%. With the temperature being above 240℃, the effective HCl yield fluctuated in a small range and reached the maximum at 280℃. As a result, according to the energy consumption and effective HCl yield, it was considered that 280 ℃ was the optimal temperature. Within a certain range, the faster of the microwave heating rate was, the higher of the dechlorination ratio. When the heating rate was increased from 4 ℃ min-1 to 13 ℃ min-1, the dechlorination ratio was raised from 57% to 67%, but the dechlorination ratio was slightly reduced when the heating rate reached up to 15 ℃ min-1. Moreover, adding SiC and graphite as microwave absorbents could significantly improve the dechlorination ratio, while SiC had better effect. At the low temperature(220℃) and relatively high temperature(280℃ and 300℃) , the enhancing dechlorination effect of SiC was more significant. The RDF was with better combustible performance and stable combustion performance after being dechlorinated and modified by microwave low temperature pyrolysis technology. In addition, the calorific value of RDF was increased to about 20 MJ/kg which was close to that of lignite and bituminous coal.