A fluorescent molecular probe CCu for Cu2+ based on biscoumarin bearing hydrazide and imine unit was designed and synthesized. The structure of CCu was identified by 1HNMR, IR, HRMS and elemental analysis, and the spectral properties of CCu was investigated. CCu exhibited Cu2+-only sensitive among metal ions such as alkali (K+, Na+), alkaline earth (Ca2+, Mg2+), and transition metal ions (Cd2+, Ag+, Fe3+, Pb2+, Cr3+, Co2+, Ni2+, Cu2+, Zn2+). The addition of Cu2+ led to a 38 nm blue-shift in absorbance maximum, a 17 nmblue-shift in fluorescence maximum , a 8.2-fold fluorescence enhancement and an obvious fluorescence change from almost colorless to blue. CCu was pH-insensitive Cu2+ fluorescent probe with the pKa of 3. 32 ± 0. 07, which could be used for Cu2+ detection in neutral and weakly alkaline pH span.