  We perform the precision calculations for the \eeqq ($q_-\bar{q}_-=u_-\bar
u_-, ~c_-\bar c_-,~ d_-\bar d_-,~s_-\bar s_-$) processes up to the QCD
next-to-leading order (NLO) including full weak decays for the final $T$-odd
mirror quarks in the littlest Higgs model with $T$-parity (LHT) at the Compact
Linear Collider (CLIC). We show the dependence of the leading order (LO) and
NLO QCD corrected cross sections on the colliding energy $\sqrt{s}$, and
provide the LO and QCD NLO kinematic distributions of final particles. The
results show that the LO cross section can be enhanced by the NLO QCD
correction and the $K$-factor increases obviously when the threshold of the
on-shell $q_-\bar{q}_-$-pair production approaches the colliding energy
$\sqrt{s}$. The $K$-factor value varies in the range of $1.04 \sim 1.41$ in our
chosen parameter space. We find that a simple approximation of multiplying the
LO kinematic distribution with the integrated $K$-factor is not appropriate for
precision study of the \eeqq ($q_-\bar{q}_-=u_-\bar u_-,~c_-\bar c_-,~d_-\bar
d_-,~s_-\bar s_-$) processes, since the NLO QCD corrections are phase space
dependent. It is necessary to calculate the differential cross sections
including full NLO QCD corrections to get reliable results.
