The invention discloses a special instantaneous power detection circuit for an electro-acupuncture therapy apparatus, and a design method of the instantaneous power detection circuit. The instantaneous power detection circuit comprises a power supply module, a channel conversion module, a signal processing module and a value display module. The power supply module supplies power to the channel conversion module, the signal processing module and the value display module; an electro-acupuncture signal passes through the channel conversion channel firstly, and two to-be-detected signals are measured in real time, so that the effectiveness is guaranteed; and secondly, voltage values at all moments are obtained through the signal processing module, and the value display module converts a voltage peak-to-peak value and a current effective value obtained by the signal processing module into instantaneous power real-time display values. Meanwhile, according to the parameters including the voltage peak-to-peak value and the current effective value needed for detection of the electro-acupuncture therapy apparatus, a load resistor, a passive attenuation circuit, a voltage amplifying circuit,a second-order Butterworth filtering circuit, a level shifting circuit, a voltage effective value reading circuit and a factor-controllable voltage amplifying module circuit in the signal processing module are designed. The instantaneous power detection circuit is specially used for the instantaneous power detection of the electro-acupuncture therapy apparatus, and has the advantages of being accurate in detection, real-time, convenient and the like.