To investigate the geometry effect on laser peen forming (LPF) for panel shaping, finite element simulation is performed with single-curved cylindrical specimens based on the eigenstrain model, and LPF experiments are conducted to verify the simulation results. The normalized deviation between the deformations of non-planar specimen and planar plate is proposed as the indicator to evaluate the geometry effect, based on which the effect of typical geometric parameters on LPF is analyzed including axial length, plate thickness, sectional arc length and sectional radius. The results show that the normalized deviation is irrelevant to the axial length when axial length is more than twice as the arc length. Moreover, the normalized deviation is observed to decrease with the increasing sectional radius, the decreasing arc length or the increasing plate thickness, respectively, when other parameters are specified.