Abstract: An electricity consumption billing method includes steps of mounting a power detection switch, recording a first average amount of electricity consumption of an electric appliance in a first time duration, recording a second average amount of electricity consumption of the electric appliance in a second time duration, and calculating an incentive amount according to the first average amount of electricity consumption and the second average amount of electricity consumption. An electric power company records the first and second average amounts of electricity consumption of the electric appliance and calculates a one-time additional incentive amount. When customers improve power utilization efficiency, not only can the amount of the electric bill be saved, but also the electric power company further offers the incentive amount to encourage customers to improve power utilization efficiency and reduce consumption of electric energy.