<p>This paper proposes a novel stopper-limited quasi-zero-stiffness isolator featuring piecewise cam negative stiffness (QSI-SP). Comprehensive static and dynamic analyses of the suspension system are respectively conducted. The derived steady-state analytical solution by the multi-scale method under the harmonic excitation demonstrates close agreement with numerical simulation. Key factors influencing the system’s vibration isolation performance and the system stability are investigated and evaluated in detail. The results show that the optimal solution for the unilateral gap of the limiter is the single-side gap of the stopper is equal to half of the straight-line segment distance of the cam. Controlling the stopper’s damping parameter to exceed its critical damping ratio significantly improves vibration isolation performance. When the excitation is within the range of the critical excitation amplitude, its amplitude can be tuned via the damping ratio of the linear viscous damping, enabling superior performance under larger excitation without focusing on the influence of damping ratio for the linear viscous damping on the absolute displacement transmissibility. Meanwhile, compared with other vibration isolation systems, the QSI-SP system demonstrates superior operational stability and ride comfort.</p>