Abstract: Lever-type elastic metamaterials have good tunability relative to conventional pure mass-spring systems, and the width and position of the bandgap can be effectively adjusted by adjusting the lever ratio. In order to broaden the vibration reduction bandwidth of the passive vibration isolation system, a lever-type nonlinear dissipative elastic metamaterial is proposed by introducing nonlinear and dissipative damping into the lever-type elastic metamaterial. This paper derives an explicit expression of the nonlinear dispersion relation using the perturbation method and investigates the band structure of nonlinear non-dissipative metamaterials with different nonlinear combinations. The effects of structural parameters on the nonlinear dispersion curves and the width and position of the band gaps are explored. A finite structure of lever-type nonlinear dissipative elastic metamaterials is constructed and various tests of its transient wave propagation are performed by numerical integration method to explore the nonlinear and damping parameters that can produce a wider elastic wave attenuation region. Numerical results show that the elastic wave attenuation region of this lever-type nonlinear dissipative elastic metamaterial increases by 81.3% with respect to the linear nondissipative metamaterials.