The coarse-grained (CG) potentials of single-walled carbon nanotubes (SWCNTs) were developed in our previous work (J.Mech.Phys.Solids,2014,71: 197-218.).However,the CG potentials can only be used to exactly obtain the linear mechanical properties of the carbon nanotube networks (CNNs) without crosslinked CNTs but not the nonlinear mechanical properties of CNNs with crosslinked CNTs,because the quadratic CG stretching and bending potentials are only considered in the CG bonded potentials.To design and assemble CNT-based flexible nanodevices in practical applications,the nonlinear mechanical behavior and failure mechanism of CNNs are extremely important and necessary.In this study,the explicit expressions of the chirality-dependent high-order nonlinear CG stretching and bending potentials in the CG bonded potentials are systematically established based on the full-atom Morse potential and the Reactive Empirical Bond-Order (REBO) interatomic potential of second generation,respectively.In particular,the CG non-bonded potentials are improved by using the 18-24 Lennard-Jones (LJ) potentials.By comparison with the full-atom molecular dynamics (MD) simulations and our analytical results,the present nonlinear CG potentials have high accuracy.The obtained nonlinear CG potentials can be used to efficiently characterize the nonlinear mechanical behaviors of CNNs with crosslinked CNTs under different loading conditions at minor computational cost.