  We investigate exotic neutrino interactions using the 205.4 kg$\cdot$day
dataset from the CDEX-10 experiment at the China Jinping Underground
Laboratory. New constraints on the mass and couplings of new gauge bosons are
presented. Two nonstandard neutrino interactions are considered: a $U(1)_{B-L}$
gauge-boson-induced interaction between an active neutrino and
electron/nucleus, and a dark-photon-induced interaction between a sterile
neutrino and electron/nucleus via kinetic mixing with a photon. This work
probes an unexplored parameter space involving sterile neutrino coupling with a
dark photon. New laboratory limits are derived on dark photon masses below
$1~{\rm eV}/c^{2}$ at some benchmark values of $\Delta m_{41}^{2}$ and
$g^{\prime2}{\rm{sin}}^{2}2\theta_{14}$.
