With thrust weight ratio increasing, integral panel is an important component to reduce the aircraft weight, and it is a great challenges to ensure the forming accuracy and mechanical property in the lager-scale panel. Laser shock forming has a great development prospect in achieving integral panel forming and improving its mechanical properties. This work investigated unequal alternate double-sided laser shock forming, which can make 7075 aluminum panel form and induce harden layer in both panel sides. The improvement in mechanical properties and microstucture evolution of 7074 aluminum panel were analyzed after unequal alternate double-sided laser shock forming. The residual stress and microhardness in surface and subsurface were verified to be enhanced by the laser shock wave. The results of XRD and EBSD provided an evidence of grain refinement. The strengthening mechanism of unequal alternate double-sided laser shock forming was analyzed in this work. The grains are distorted and refined during high strain rate plastic deformation due to dislocation slip and accumulation. The mechanical properties were enhanced by unequal alternate double-sided laser shock forming for harden layers in both panel sides. The harden layers and grain refinement has a great significance in inhibiting the crack generation and growth.