Laboratory experiments were carried out to determine the permeability coefficient of permeable bricks under specific experimental conditions. And an analysis of its changing characteristics and causes was made. The results show that the permeable brick will have obvious blockage after being used for a period of time, and will loss the infiltration capacity in severe cases due to high suspended matter content in the urban rainwater runoff. Further experiments were made to probe the effects of improved permeability of permeable brick by surface sediment cleaning method. The results show that this method has a certain recovery effect, but the effect is limited.