We propose and demonstrate a shape-controlled metagrating with adjustable energy distribution based on shape memory Polymers (SMPs). The design consists of a capacitance printed on the top of the FR4 substrate, SMPs substrate (VeroWhitePlus) in the middle layer, and a metallic ground at the bottom. Using the perfect diffraction theory to design reconfigurable metagratings based on shape memory polymers is. Furthermore, the functionalities of the designed shape-controlled tunable metagrating are investigated by full-wave simulations. Simulation results show that the reconfigurable metagrating can achieve energy bisection of +1, -1 order and the energy trisection of +1, 0, -1 order. And the proposed reconfigurable metagrating is experimentally demonstrated. The design breaks through the limitation that the traditional electrically tunable reconfigurable metagratings need external power supply, and provides a new design idea for the dynamic control of energy distribution of the reconfigurable metagratings.