In speech enhancement algorithm based on generalized sidelobe canceller (GSC), when there is an error in direction estimating, the target speech cannot be blocked by blocking matrix (BM) module completely. Then in the multiple-input canceller (MC) module, the target speech will be eliminated, which will cause the leakage of the target speech. In this paper, a new optimization algorithm is proposed for the leakage of the speech caused by the error of signal direction of arrival (DOA). First, we adjust the spectrum of the signal with time delay compensation, then the blocking matrix would be adjusted adaptively according to the characteristics of the correlation between the final output of MC module and the output of BM module. The estimated direction can be closer to the real target speech direction in order to reduce the leakage of the target speech. Simulation results show that the proposed algorithm has better speech enhancement performances in both objective and subjective evaluations.