The invention relates to a method and system for calculating the sequence of fundamental component sampled signals of electric signals. The electric signals comprise direct-current components, fundamental components and harmonic components of higher than the second order. The method comprises the following steps: setting a first parameter K1, a second parameter K2 and a third parameter K3; filtering the harmonic components of higher than the second order in the electric signals to obtain filtered electric signals; sampling the filtered electric signals to obtain the sequence Q[j] of sampled electric signals by using time T as a sampling period, wherein the j sampled electric signal is Qj, and the sequence number j is an integral number not smaller than 0; and calculating the sequence Q1[j] of the fundamental component sampled signals of the electric signals based on K1, K2, K3 and Q[j], wherein the (j+1) fundamental component sampled signal Q1, j+1=K1Qj+K2Qj+1+K3Qj+2. By using the technical scheme, the complexity of filtering direct-current components can be reduced.