The non-thermal effect in the process of low-temperature microwave dechlorination of PVC was explored by the same initial and final temperature comparison method in effect difference method, in terms of microwave heating and conventional electric heating according to the index of dechlorination rate, proportion of HCl yield, dechlorination char characteristics, energy yield and heating energy consumption. It was found that under the same final temperature, the dechlorination efficiency of PVC by microwave heating was slightly higher than that by electric heating, and the proportion of HCl yield by microwave heating was significantly higher than that by electric heating. Except for the condition of 220 ℃, the content of C and H by electric heating was slightly lower than that by microwave heating, while the content of Cl and O was significantly higher, and the energy yield of dechlorination char by microwave heating was higher. It revealed that there was little difference in dechlorination effect between the two heat sources at low temperature. Therefore, it was considered that non-thermal effect was unattainable and the difference between the two heat sources was mainly caused by the microwave thermal effect.