  The proton-proton ($pp$) fusion chain dominates the neutrino production from
the Sun. The uncertainty of the predicted $pp$ neutrino flux is at the
sub-percent level, whereas that of the best measurement is $\mathcal{O}(10\%)$.
In this paper, we present the first result to measure the solar $pp$ neutrinos
in the electron recoil energy range from 24 to 144 keV, using the PandaX-4T
commissioning data with 0.63 tonne$\times$year exposure. The $pp$ neutrino flux
is determined to be $(8.0 \pm 3.9 \,{\rm{(stat)}} \pm 10.0 \,{\rm{(syst)}}
)\times 10^{10}\, $$\rm{s}^{-1} \rm{cm}^{-2}$, consistent with Standard Solar
Model and existing measurements, corresponding to a flux upper limit of
$23.3\times 10^{10}\, $$\rm{s}^{-1} \rm{cm}^{-2}$ at 90\% C.L..
