Disclosed is an active factor set membership proportional sub band self-adaption echo cancellation method. The method comprises the steps: A, dividing an adaptive echo cancellation sub band filter input vector X(n) formed by a discrete value of a far-end signal into a sub band signal X(n), B, performing N extraction on an input sub band signal X(n) and a near-end sub band signal d(n) to obtain a signal X(k) after the extraction and a d(k), C, obtaining a filtering value y(k) of the signal X(k) after the extraction via an adaptive echo cancellation sub band filter, D, subtracting a filtering value y(k) from the near-end sub band signal d(k), with an echo, after the extraction and then sending a different value to a far end, E, obtaining a sub band filter step length u(k) through calculation of an active factor f<l>(k) and a proportional matrix G(k) by utilizing a set membership filtering algorithm, and updating a weight coefficient vector W(k), and F, enabling k to meet an expression k=k+1, and repeating A-E steps until an end of a call. The method has the rapid convergence speed and the low steady-state error at one aspect, and has the rapid tracking capability at the other aspect; and the method has the good cancellation effect on an acoustic echo of a communication system.