For the first time, Nano ZnGa2O4:Cr3+ phosphor has been synthesized through sol-gel-combustion of precursor incorporating Cr3+ into gallic acid compound matrix. After pyrolysis and combustion, upgraded material preparation method, which is simple, time saving and energy saving, namely ZnGa2O4:Cr3+, to obtain nano materials. The nano phosphor with special structure exhibits significantly enhanced persistent luminescence properties, over 2 h within the near-infrared range, and will permit bright and reliable imaging compared with that of sol-gel one. Moreover, this phosphor with persistent luminescence and photoluminescence properties, simultaneously, will have significant implications for comprehensive practical applications and multifarious biomedical investigations and systems.