The present disclosure relates to a time-division multiplexing (TDM)-based multi-channel electrocardiogram measurement apparatus and method, which remove the influence of power line interference in a way to implement multiple channels by using a TDM method, remove an electrode DC offset (EDO) through a pre-charged capacitor, and periodically take a current out or supply a current. The TDM-based multi-channel electrocardiogram measurement apparatus and method robust against power line interference according to the present disclosure have advantages in that it can measure electrocardiogram by using multiple channels with low power and high integration based on TDM, can perform contactless measurement because an EDO is efficiently eliminated and high impedance is satisfied, and has a characteristic robust against power line interference.