  Motivated by the recent supersymmetry (SUSY) search results which prefer most
SUSY particles heavy, and muon g-2 anomaly which prefers colorless SUSY
particles light, we explore the status of a light smuon (the SUSY partner of
left-handed muon lepton) in the Next-to-Minimal Supersymmetric Standard Model
(NMSSM). Assuming colored SUSY particles be heavy, and considering numerous
experimental constraints including muon g-2, SUSY searches, and dark matter, we
scan the parameter space in the NMSSM with Z3-symmetry, checking the status of
colorless SUSY particles and their possible mass order, and paying special
attention to the smuon. After calculation and discussions, we draw the
following conclusions: (i) The dominated SUSY contributions to muon g-2 come
from the chargino-sneutrino loops, but the muon g-2 anomaly can also constrain
the mass of smuon seriously because of the mass-degenerate relation between
smuon and muon sneutrino. To interpret the muon g-2 anomaly at $1\sigma$
($2\sigma$) level, the smuon need to be lighter than 1 TeV (1.8 TeV). (ii) When
$\tilde{\chi}^0_1$ is wino- or higgsino-dominated, the smuon can escape from
the direct searches with low mass, e.g., 300 GeV. (iii) When smuon and
$\tilde{\chi}^0_1$ are mass-degenerate, the smuon can be as light as 200 GeV,
while the $\tilde{\chi}^0_1$ is usually bino-dominated, or some
singlino-dominated, and its relic density can most likely reach the observed
value, and the dominated annihilating mechanism is slepton annihilations. In
addition, we also list several benchmark points for further studies.
