In response to the problems of narrow light response range and low energy utilization in the use of fluorescein dyes alone,anion-cation dye pair-based light capture system is constructed by utilizing the electrostatic interaction between ionic dyes.The catalytic performance of the system in the cross-dehydrogenative coupling(CDC)reaction and the corresponding influence factors are investigated.The results demonstrate that a stable light-harvesting system can be formed by the interaction between cationic and anionic dyes.A light-capturing system termed"DAO+ARB-"with a concentration of 2×10-5 mol·L-1 is constructed through using Rose Bengal(RB),a cationic dye,and Auramine O(AO),an anionic dye as acceptor and donor,respectively.The fluorescence resonance energy transfer(FRET)efficiency of"DAO+ARB-"reaches 72%.FRET process of the light capture system can effectively broaden the light response range and enhance the photocatalytic performance of the acceptor.The"DAO+ARB-"system exhibits excellent photocatalytic performance for CDC reaction,and its photocatalytic reaction rate is about 1.60 times that of the catalyst with RB only.