Abstract: An equivalent circuit of ferroelec tric liquid crystaloptically addressed spatial light modulator was presented.Choosing write light and erase light as reference variabl es,opto-electronic characteris-tics of the spatial light modulator was simulated with the help of Pspice and an analytic software of circuit.The resultsindicate that the climbi ng time gained by circuit simulation is measured in microsecond,and the critical value of erase effect should be controlled in mW/cm²;meanwhile the opto-electronic res-pondent time is varied with the accre tion of write（erase）light intensity.The se are coincident with the experimental results according to related papers.