Mobile　ions　is　important　for　the　performance　of　perovskite　solar　cells　(PSCs).　To　investigate　the　impact　of　mobile　ions　within　PSCs,　this　study　employed　the　Driftfusion　model　to　explore　the　mobile　ions　behavior,　specifically　iodine　vacancies　inherent　to　perovskite　structures.　Our　findings　indicated　that　a　decrease　in　vacancy　densities　correspond　to　a　decrease　in　open　circuit　voltage　(Voc)　and　an　increase　in　short-circuit　currents　(Jsc)　and　efficiency.　Under　open-circuit　condition,　an　ionic　field　is　established　within　the　device,　modulating　electron　and　hole　distributions,　thereby　influencing　band　alignment　and　quasi-Fermi　levels,　which　results　in　decreased　Voc.　Under　short-circuit　condition,　the　ionic　field　generated　by　mobile　ions　significantly　impacted　carrier　recombination　dynamics,　leading　to　diminished　Shockley-Read-Hall　(SRH)　recombination,　thus　elucidating　the　observed　rise　in　Jsc.　Considering　the　reported　relationship　between　light　soaking　effect　and　the　mobile　ion　density,　our　result　unveil　a　potential　path　to　quantitatively　analyzing　the　light　soaking　effect　of　PSCs.　©　1980-2012　IEEE.