Abstract: The length of the rock blot are one of the important parameters to evaluate the quality of the rock bolt,during rock bolt detection,because of the harsh environment and the disturbance from instrumentation,there are a lot of noises,which make the signal analysis and rock bolt parameters detection difficult,so,it’s necessary to remove noises.According to the characteristics of the anchor signal distribution,this paper proposes a detection method based on spectral kurtosis in parameter detection.A filter on the basis of the maximum SNR filtering using spectral kurtosis theory is constructed,parameters testing are finished after filtered.Compared with the traditional method based on wavelet theory,the detection precision of this method has been greatly improved.The denoised signal also has a good frequency domain characteristic,some frequency values are easy to get,so the length of anchor could be got using a frequency differential method.