<p>The lattice strain is considered critical for determining the catalytic activity of metal catalysts such as Pt. However, the dynamic manipulation of Pt lattice strain under reaction conditions to directly examine its catalytic effect has not been achieved. In this study, we realized the reversible manipulation of Pt electrocatalytic properties under electrochemical conditions by tuning the Pt lattice strain with the temperature-controlled Martensite-Austenite phase transition of the shape memory NiTi alloy substrate. This enabled establishing a straightforward relationship between the strain-induced electronic structure transformation and electrocatalytic activity leaping. The binding strength between Pt and surface oxygen species was confirmed as the critical factor that dominated the hydrogen evolution and the oxygen reduction activities. In contrast, the oxygen evolution activity was barely affected by NiTi substrate phase transition.</p>