  A self-consistent gravitational quantum field theory, with gravitational
force treated on the same footing as the other three fundamental interactions,
was established recently. The gravidynamics predicted by such a theory could
lead to important implications, and the comparisons with experimental results
may provide us opportunities to test such new approach of gravity based on the
framework of the quantum field theory of gauge interactions. In this work, we
start with the effective field equation of the gravitational quantum field
theory, and then solve the perturbative gravigauge field order by order up to
the 1st post-Newtonian level under the assumption of a simplified
energy-momentum tensor of perfect fluids. Having the constraints on the related
post-Newtonian parameters from the most up-to-date observational data, the new
bound on the combined coupling in the gravitational quantum field theory
$|\gamma_G(\alpha_G-\alpha_W/2)| \leq (2.4\pm30)\times10^{-6}$ is obtained.
Under such bound, we found that the new gravitational quantum field theory
successfully passed and found no conflict with the contemporary keynote Solar
system experiments of gravity.
