Abstract: The stilling basin protection structure plays as a first line of defense for dam safety, and the safety of the stilling basin and spillway becomes a safety premise of the dam. Based on the Xiangjiaba physical model, the model tests on the pervious base slab with keyway have been carried out in this study, in combination with "active protection" and "passive defense". And the characteristics of the pulsating water pressure from the groove, the distribution law of the pulsating pressure on the lower surface, the spatiotemporal correlation, the spatial correlation and the pressure spectrum characteristics of the pervious base slab with keyway are analyzed in this paper. The model tests results show that the the maximum values of the measured pulsation pressures on the lower surface and vertical groove of the pervious base slab with keyway have slightly decreased after addition of the permeable holes at the water jump stable region; the pulsation pressure coefficients measured at the measuring points located on the lower surface and the vertical groove of the pervious base slab with keyway have slightly decreased; the correlation between the measuring points located on the lower surface have also slightly decreased and at the same time the vortex space integral scale and maintenance have been reduced; and the power spectral density measured at the lower surface and the measuring points on the keyway has been reduced and it tends to have lower frequency.