  High-energy spin-polarized electron, positron, and $\gamma$-photon beams have
many significant applications in the study of material properties, nuclear
structure, particle physics, and high-energy astrophysics. Thus,efficient
production of such polarized beams attracts a broad spectrum of research
interests. This is driven mainly by the rapid advancements in ultrashort and
ultraintense laser technology. Currently available laser pulses can achieve
peak intensities in the range of $10^{22}-10^{23}$ Wcm$^{-2}$, with pulse
durations of tens of femtoseconds. The dynamics of particles in laser fields of
the available intensities is dominated by quantum electrodynamics (QED) and the
interaction mechanisms have reached regimes spanned by nonlinear multiphoton
absorbtion (strong-field QED processes). In strong-field QED processes, the
scattering cross sections obviously depend on the spin and polarization of the
particles, and the spin-dependent photon emission and the radiation-reaction
effects can be utilized to produce the polarized particles. An ultraintense
laser-driven polarized particle source possesses the advantages of
high-brilliance and compactness, which could open the way for the unexplored
aspects in a range of researches. In this work, we briefly review the seminal
conclusions from the study of the polarization effects in strong-field QED
processes, as well as the progress made by recent proposals for production of
the polarized particles by laser-beam or laser-plasma interactions.
