A digital power meter apparatus and the method for the same are proposed. The input voltage signal and input current signal through dual channels are processed at a first stage to obtained a first digital signal. The first digital signal is sent to a third low-pass filter. The input voltage signal and input current signal are processed in a second-stage processing through a first low-pass filter, a second low-pass filter and a second logic operation unit to obtain a second digital signal. A third logic operation unit processes the first digital signal and a second digital signal in order to obtain a digital power signal proportion to the product of the two input signals.