In order to clarify the low power factor impact on energy metering, this paper analyzes the relation between power factor and power quality from a theoretical perspective firstly. Secondly, it studies the load of resistive, inductive and capacitive consumption the active energy under different power factor but the same apparent power. Experimental results show that the lower the power factor of electrical equipment, the greater the error of energy metering device, and the larger reactive power generated, reducing the efficiency of power generation equipment, increasing the loss of the line.