This paper focuses on thermal-structural analysis and lightweight design of actively-cooled panels reinforced by low density lattice-framed material truss cores. Numerical models for actively-cooled panels are built up with parametric codes to perform the coupled thermal-structural analysis considering the internal thermal environment of convective heat transfer in the combustor and convective heat transfer in the cooling channel and internal pressures from the combustion gas and the coolant. A preliminary comparison of the LFM truss reinforced actively-cooled panel and the non-reinforced panel demonstrates that the thermal-structural behavior is significantly improved. Then an optimization procedure is carried out to find the lightest design while satisfying thermal deformation and plastic strain constraints with thicknesses of face sheets and topology parameters of LFM truss as design variables. The optimization result demonstrates that compared with the non-reinforced actively-cooled panels weight reduction for the panel reinforced by LFM truss may reach 19.6%. We have also fabricated this type of actively-cooled panel in the laboratory level and the specimen shows good mechanical behaviors.