The persistent spin helix(PSH)system is considered to have promising applications in energy-conservation spintronics because it supports an extraordinarily long spin lifetime of carriers.Here,we predict that the existence of PSH state in two-dimensional(2D)ferroelectric NbOI2 monolayers.Our first-principles calculation results show that there exists Dresselhaus-type spin-orbit coupling(SOC)band splitting near the conduction-band minimum(CBM)of the NbOI2 monolayer.It is revealed that the spin splitting near CBM merely refers to out-of-plane spin configuration in the wave vector space,which gives rise to a long-lived PSH state that can be controlled by reversible ferroelectric polarization.We believe that the coupling characteristics of ferroelectric polarization and spin texture in NbOI2 provide a platform for the realization of fully electric controlled spintronic devices.