^a College of Life Science and Chemistry, Dali University, Dali, Yunnan 671000, China 
^b Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan 671000, China
^c State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China

A new scheme of photo-fluorescent emission origin, described as S0 (relaxed state)→Sn (Frank-Condon state)→ Sm (relaxed state)→S0 (Frank-Condon state), is presented to explain the multiple fluorescent emissions of squaraine dyes observed experimentally according to the configuration interaction singles calculations of relaxed excited states of a model compound, bis[4-(N,N-dimethylamino)phenyl]squaraine (SQ). It is exhibited that all triple fluorescent emissions of SQ have their significant origin in vertical electron transitions of different relaxed excited states. In addition, some important absorption peaks appearing in higher energy region are most likely to be responsible for the higher energy band observed in solid states of many squaraine dyes.