Abstract: The temporal profiles of two beams were obtained using comparison method , and then the energy reduction factor was acquired. The two beamsone passing through a transparent medium is clipped by laser-induced plasma, and the other transmits with a delay line come into a set of photo-electricity conversion component and oscillographin simultaneously. It is shown that the transmitted pulse energy reduction factor is 12 to 14 with the 1.064 m 1 ns laser pulse, a 100 mm focal length lens, a 100 m thick fused silica plate, and a pinhole of 80 m radius to ensure that the entire apertured area is from the plasma shuttered focal plane. Changing the thickness of the fused silica plate and the radius of the apertured pinhole respectively shows no impact on the energy reduction factor. The energy reduction factor increases while the energy of input beam enhances and the trailing edge of the clipped pulse gradually falls faster. The temporal profile of original laser pulse was reconstructed by profile stitching at the point of energy reduction.