Abstract: Membrane structures are widely used in the fields such as flexible electronics and deployable structures, yet their insufficient bending stiffness often induces wrinkles, leading to electronic device damage or reducing propulsion efficiency. Existing wrinkle suppression approaches, though effective, suffer from effective area loss or from complicated manufacturing processes. This study proposes a wrinkle-free design method through functionally graded Young's modulus distribution. An optimization model minimizing negative principal stress area was established, with optimal gradient parameters determined using a multi-island genetic algorithm. The optimized solution demonstrates excellent wrinkle suppression performance and robustness in nonlinear finite element simulations, with its distribution closely matching a hyperbolic tangent function. Building on this foundation, a hyperbolic tangent empirical model was constructed, with optimal solutions derived considering actual material parameters. The designed gradient structure was fabricated via spatioselective ultraviolet (UV) exposure, with experimental results validating the design effectiveness. The superposition principle in elastic mechanics qualitatively reveals the wrinkle suppression mechanism. This research provides a zero-area loss and fabrication friendly solution for engineering membrane structures.