In order to research the propagation characteristics of laser shock wave in aluminum alloy sheet,numerical simulation method is used.The paper analyses the propagation characteristics of shock wave in 3003 aluminum alloy sheet through path of different nodes.The result shows that in initial phase of laser loading,maximum stress appears on the edge of laser spot on sheet surface while only small fluctuation occurs in central area.After 1000 ns,the stress in central area increases to 200 MPa when surface wave propagates to the position that corresponds to concave die.At the same time,plastic deformation increases while sheet deformation is uneven,which would cause thinning failure.In laser shock direction,the pressure wave propagates to the free surface of sheet and returns tensile wave after 60 ns.At about 102 ns,the tensile stress reaches maximum value of 1782 MPa,which is liable to cause spallation failure.The results are important for improving aluminum alloy forming performance by laser shock.