  Searching for the top squark (stop) is a key task to test the naturalness of
SUSY. Different from stop pair production, single stop production relies on its
electroweak properties and can provide some unique signatures. Following the
single production process $pp \to \tilde t_1 \tilde{\chi}^-_1 \to t
\tilde{\chi}^0_1 \tilde{\chi}^-_1$, the top quark has two decay channels:
leptonic channel and hadronic channel. In this paper, we probe the
observability of these two channels in a simplified MSSM scenario. We find
that, at the 27 TeV LHC with the integrated luminosity of ${\cal L} =
15~\text{ab}^{-1}$, $m_{\tilde{t}_1}<1900$ GeV and $\mu<750$ GeV can be
excluded at $2\sigma$ through the leptonic mono-top channel, while
$m_{\tilde{t}_1}<1200$ GeV and $\mu<350$ GeV can be excluded at $2\sigma$
through the hadronic channel.
