  We present a highly efficient lattice Boltzmann (LB) kinetic model for
thermal liquid-vapor system. Three key components are as beow: (i) a discrete
velocity model by Kataoka \emph{et al.} [Phys. Rev. E \textbf{69},
035701(R)(2004)]; (ii) a forcing term $I_{i}$ aiming to describe the
interfacial stress and recover the van der Waals equation of state by Gonnella
\emph{et al.} [Phys. Rev. E \textbf{76}, 036703 (2007)]; and (iii) a Windowed
Fast Fourier Transform (WFFT) scheme and its inverse by our group [Phys. Rev. E
\textbf{84}, 046715 (2011)] for solving the spatial derivatives, together with
a second-order Runge-Kutta (RK) finite difference scheme for solving the
temporal derivative in the LB equation. The model is verified and validated by
well-known benchmark tests. The results recovered from the present model are
well consistent with previous ones[Phys. Rev. E \textbf{84}, 046715 (2011)] or
theoretical analysis. The usage of less discrete velocities, high-order RK
algorithm and WFFT scheme with 16th-order in precision makes the model more
efficient by about $10$ times and more accurate than the original one.
