Developing strain sensors with both high sensitivity and high linearity has always been the goal of researchers. Compared to resistive strain sensors, capacitive strain sensors have incomparable linearity advantages but have always been limited by low sensitivity. Here, we report a gradient stiffness sliding design strategy that addresses this problem, significantly improving sensitivity while maintaining high linearity. A strain sensor with excellent performance is successfully prepared, exhibiting a giant gauge factor (9.1 × 10⁴) and linearity (R² = 0.9997) over the entire sensing range, together with almost no hysteresis and fast response time (17 ms). The gradient stiffness sliding design is a general strategy expected to be applied to other types of sensors to achieve ultra-high sensitivity and ultra-high linearity simultaneously.