The variable relation of the coefficient variance of wavelet transformation of 1/f fractal signal in white noise versus the scale is adequnately modified to develop a novel method based on least\|squares to estimate the parameters of 1/f noise of semiconductor laser diodes （LDs）. The measured data indicate that this method can effectively extract the 1/f noise submerged in white noise of LDs, and the estimated 1/f signal is in better accordance with the measured results of the contrast apparatus.