<p>Cam-roller mechanisms are commonly used in translational and rotational quasi-zero-stiffness (QZS) vibration isolators. However, typical cam-roller mechanisms suffer from large frictional damping, a QZS range limited by cam dimensions, and degrees of freedom coupling. Here, we propose a novel cam-roller mechanism (NCM) with bi-directional decoupling using rotating rods and torsion springs as elastic components, and demonstrate its feasibility for bidirectional low-frequency vibration isolation. By designing a specific cam profile, an extremely wide range of vertical linear and rotational quasi-linear low stiffness is achieved, ensuring excellent low-frequency vibration isolation performance under bi-directional excitation. Static analyses show that the two-directional motions only affect each other’s low-stiffness range, with a large decoupling displacement interval. The system dynamics equations are established based on the original expression of the restoring force, and the Alternating frequency–time harmonic balance method is used to solve the equations quickly to avoid the Taylor fitting error. Dynamic analyses show the NCM has good adaptability to excitation amplitude, damping, and load deviation. The two-direction decoupling property makes the vibration isolation performance in one direction almost unaffected by the other direction. Compared with conventional cam-roller mechanisms, the NCM has a smaller cam size and smoother profile. Besides, the NCM has a wider QZS range and better low-frequency isolation than three-spring QZS isolators, X-shaped isolators, and linear isolators. Static and dynamic test results verify the correctness of the theoretical analysis and confirm the NCM’s wide low stiffness range and excellent low-frequency vibration isolation performance. The principles of this work can be used to design versatile cam-roller vibration isolators with many potential applications.</p>