Next generation petawatt laser facility is expected to reach intensity up to the order of 10²³-10²⁴ W·cm^-2,which may generate electromagnetic fields so strong that nonlinear quantum electrodynamics (QED) processes play a crucial role in plasma dynamics.A large number of γ photons can be emitted through synchrotron radiation from ultrarelativistic electrons,and pair creation process can also be triggered when γ photons traverse electromagnetic fields.In turn,these QED physics can affect plasma dynamics itself significantly,in particular for electron motion under radiation reaction.In order to study such extreme plasma dynamics,we introduce a QED model developed in recent years,which can be coupled with traditional particle-in-cell (PIC) code,i.e.,so-called a QED-PIC code.Due to booming particle number caused by the newly emitted photons and created pairs,we also develop a particle merge algorithm to reduce the computational scale.Several applications of this contemporary QED-PIC code in modeling of ultraintense laser-plasma interaction and extreme astrophysical phenomena are presented.