  With the measurements of the decay $D^+_s \rightarrow K^0_S K^0_S \pi^+$ by
the BESIII Collaboration, we investigate this three-body weak decay via the
chiral unitary approach for the final state interaction, where the resonances
$S(980)$ and $S(1710)$ are dynamically reproduced with the interaction of
eleven coupled channels, and the $W$-external and -internal emission mechanisms
are considered at the quark level. Besides, we also take into account the
contribution from the $P$-wave resonance $K^*(892)^+$ and make a combined fit
of the $K^0_S K^0_S$ and $K^0_S \pi^+$ invariant mass spectra measured by the
BESIII Collaboration. The fitted results show that the enhancement around 1.7
GeV in $K^0_S K^0_S$ mass spectrum is overlapped with two visible peaks,
indicating the mixing signal originated from the resonances $a_0(1710)$ and
$f_0(1710)$ due to their different poles (masses). Thus, the decay $D^+_s
\rightarrow K^0_S K^0_S \pi^+$ is helpful to reveal their molecular nature with
the mixing signal, which can be more precisely measured in the future.
