  In this paper, for a class of $ d $-dimensional $ G $-Brownian motions, we
introduce $ G $-Bessel processes. Under the condition of dimensionality $ d $,
we obtain that the $ G $-Bessel process is the solution of a stochastic
differential equation. Moreover, under the more strict condition of
dimensionality $ d $, we get the uniqueness of the solution of stochastic
differential equations governing $ G $-Bessel processes and the
nonattainability of the origin of $ G $-Brownian motion.
