  We present a detailed study of the production and decay of the excited quark
at the QCD next-to-leading order (NLO) level at the Large Hadron Collider,
using the narrow width approximation and helicity amplitudes method. We find
that the QCD NLO corrections can tighten the constraints on the model
parameters and reduce the scale dependencies of the total cross sections. We
discuss the signals of the excited quark production with decay mode
$q^{\ast}\rightarrow q\gamma$ and $q^{\ast}\rightarrow qg$, and present several
important kinematic distributions. Moreover, we give the upper limits of the
excited quark excluded mass range and the allowed parameter space for the
coupling constants and the excited quark mass.
