A highly accuracy internally multi-reference configuration interaction method (icMRCI) was used to calculate potential curves of low-lying electronic states and transition dipole moment of A³П-X³Σ^- system for OH⁺ ion. Davidson correction (MRCI+Q) of energy and scalar relativistic effect were considered in the calculation. Based on potential energy curves of low-lying electronic states spectroscopic parameters were determined by solving one-dimensional radial Schr dinger equation of nuclear motion. Einstein coefficient and F-C factor of A³П-X³Σ^- transition system are calculated by using the transition dipole moment. Moreover, radiative lifetimes of A³П(ν'=0-6) vibration states were studied. It shows that the radiative lifetimes are of the order of 10^-6 s.