  The galactic 511 keV gamma-ray line has been observed since 1970's, and was
identified as the result of electron-positron annihilation, but the origin of
such positrons is still not clear. Apart from the astrophysical explanations,
the possibilities that such positrons come from dark matter (DM) annihilation
are also widely studied. Primordial black hole (PBH) is also an extensively
studied candidate of DM. If PBHs exist, the DM particles may be gravitationally
bound to the PBHs and form halo around PBHs with density spikes. DM
annihilation in these density spikes can enhance the production rate of
positrons from DM particles, but the signal morphology is similar to the
decaying DM. We consider such a mixed model consisting of DM particles and PBHs
and obtain the upper limit from the data of 511 keV gamma-ray line from
INTEGRAL/SPI on the decaying component of DM particles and the constraint on
the PBH abundance. These constraints are general and independent of particle DM
models. For the mixed model consisting of excited DM and PBHs, the constraints
on the PBH abundance can be down to $O(10^{-17})$ for DM particle with mass
around $1~\mathrm{TeV}$, which is more stringent than that obtained from the
extragalactic gamma-ray background.
