Inspired by creatures reducing impact damage, a novel semi-active protection strategy to enhance impact resistance through structural adjustment is proposed. The heat-activated shape memory composites (PCLE) consisting of polycaprolactone (PCL) and shear stiffening elastomer are first prepared. The PCLE with 50 wt.% PCL (PCLE-50%) presents tensile strength of 0.46 MPa, fracture strain of 148%, high shape fixity and recovery rates (97.9% and 91.1%), and stable shape-memory repeatability. Furthermore, various PCLE-50%-based structures are fabricated, which show reinforced anti-impact performance after shape-shifting. Loading from 300 mm, the maximum drop hammer impact force of no protection, PCLE-50%, and deformed assembled single-branch structure are 3.98 kN, 1.75 kN, and 0.93 kN, respectively. Additionally, assembled complex structures also exhibit exceptional energy absorption properties. Ultimately, intelligent clothing is successfully manufactured. Besides good anti-impact effect, the clothing shows excellent thermal insulation capabilities whose surface temperature is 31.7 °C after heating for 600 s at 42 °C. This study provides an innovative means to develop deformable, wearable, and intelligent protective devices.