Abstract: CuI solid electrolyte films were prepared by dipping coating method.DSSC was made with CuI films as solid electrolyte.Surface morphology and resistance rate of CuI solid electrolyte film were investigated by SEM and four probes resistance rate instrument.The performance of DSSC was measured by XJCM-8 apparatus.The results indicate that the growth of CuI crystal particles can be inhibited;the matching of crystal particles size of CuI and pores size of porous TiO₂ films can be improved;resistance rate of CuI film can be reduced gradually by adding appropriate content of ionic liquid,which are important factors on DSSC’s performance and stability with CuI solid electrolyte.