For achieving adaptive deformation and lightweight for wind turbine blade, the leading edge of the blade is designed with a compliant mechanism. Aiming to minimize the amount of materials, taking the departures between the actual and target displacements and the maximum stress as restraints, variable density method is used to topologically optimize the compliant mechanism. A two-way shape memory alloy wire is used to drive the optimized leading edge to deform adaptively. The research results verify the reliability of the compliant mechanism and topology optimization, and provide reference for the compliant mechanism design and topology optimization of large wind turbine blades. Meanwhile, it has verified that the two-way shape memory alloy wire is a promising intelligent driver for engineering applications.