  Taking advantage of the Photometric objects Around Cosmic webs (PAC) method
developed in Paper I, we measure the excess surface density
$\bar{n}_2w_{{\rm{p}}}$ of photometric objects around spectroscopic objects
down to stellar mass $10^{8.0}M_{\odot}$, $10^{9.2}M_{\odot}$ and
$10^{9.8}M_{\odot}$ in the redshift ranges of $z_s<0.2$, $0.2<z_s<0.4$ and
$0.5<z_s<0.7$ respectively, using the data from the DESI Legacy Imaging Surveys
and the spectroscopic samples of Slogan Digital Sky Survey (i.e. Main, LOWZ and
CMASS samples). We model the measured $\bar{n}_2w_{{\rm{p}}}$ in N-body
simulation using abundance matching method and constrain the stellar-halo mass
relations (SHMR) in the three redshift ranges to percent level. With the
accurate modeling, we demonstrate that the stellar mass scatter for given halo
mass is nearly a constant, and that the empirical form of Behroozi et al
describes the SHMR better than the double power law form at low mass. Our SHMR
accurately captures the downsizing of massive galaxies since $z_s=0.7$, while
it also indicates that small galaxies are still growing faster than their host
halos. The galaxy stellar mass functions (GSMF) from our modeling are in
perfect agreement with the {\it model-independent} measurements in Paper III,
though the current work extends the GSMF to a much smaller stellar mass. Based
on the GSMF and SHMR, we derive the stellar mass completeness and halo
occupation distributions for the LOWZ and CMASS samples, which are useful for
correctly interpreting their cosmological measurements such as galaxy-galaxy
lensing and redshift space distortion.
