Abstract: Pre-freezing is one of the method to set samples while the general method is not applicable to the special soil.As for the decayed wood mixed silt soil,the routine methods would disturb and break away the decayed wood and silty soil.Samples were set with pre-freezing to perform the tests such as consolidation,secondary consolidation,compression tests and so on.Through the comparison between the results with those obtained by common methods,the effect of the refrigeration method to the parameter of the decayed wood mixed silty soil was shown,and it was concluded that and pre-freezing was more adaptable to the soil with many decayed wood.