Embodiments of the invention disclose a speech de-noising method and a speech de-noising device. The method comprises the following steps: detecting the speech of a speech signal with noise to distinguish between speech frames and non-speech frames; estimating the noise of the speech frames and the noise of the non-speech frames to get a noise power spectrum fused estimated value, wherein the noise power spectrum fusion estimated value is the fused value of the noise power spectrum estimated value of the speech frames and the noise power spectrum estimated value of the non-speech frames; and de-noising the speech signal with noise according to the noise power spectrum fusion estimated value. According to the technical scheme provided by the embodiments of the invention, the noise of the speech frames and the noise of the non-speech frames are estimated, and the speech signal with noise is de-noised based on the noise estimation results of the speech frames and the non-speech frames. Thus, the de-noising effect of the existing speech de-noising scheme is improved effectively, and the quality of speech is improved.