Abstract: To solve precision forming problem of the antenna panels with large non-developable double-curvature surface, the precision forming principle was proposed, based on "discrete nails die, vacuating press, honeycomb sandwich, stressrelease in-plane, and springback compensation". The problem of rectangle thin plate with free edges and constrained at arbitrary inner points with large deflection was discussed. An explicit/implicit hybrid FEM method was used to simulate the forming process and springback to determine the processing parameters. The slotting and notching techniques were developed for releasing the compression stresses of panel in order to ensure good fittability of panel on nails die. The compensation of springback has carried out by modifying discrete nails die, the adjusting coefficient of nail-head height was obtained by minimizing the shape-error between modified surface and simulation shape. The CAE system for precision forming of antenna panels was developed and was used successfully in several actual projects of compact antenna test range and millimeter-wave antenna. The precision of reflector panel can reach below 25 μm.