  A series of $1T$-Fe$_x$Ta$_{1-x}$SSe (0 $\leq x \leq$ 0.1) single crystals
was fabricated via the chemical-vapor-transport (CVT) method and investigated
by structure, transport, and magnetic measurements along with the
density-functional-theory (DFT) calculations. The superconductivity (SC) in
parent $1T$-TaSSe can be gradually suppressed by Fe-substitution ($x\leq0.03$),
accompanied by the disappearance of charge-density-wave (CDW). DFT calculations
show that the Fe-substitution effectively inhibits the CDW superstructure and
thereby the CDW domains are destroyed. With further increasing $x$ ($x>0.03$),
the disorder-induced scattering increases, and the system enters into the
possible Anderson localization (AL) state. Our results prove the SC develops in
the CDW phase and coexists with the CDW domain in $1T$-TaSSe system.
