This work explores the role of geometric phase (GP), which results from light induced conical intersection (LICI), in photodissociation process of the D2+ molecule through solving the time‐dependent Schrödinger equation. The dissociation results between two cases including GP and excluding GP are compared. Different from the case including GP, the angular distribution of photofragments excluding GP is non‐vanishing at θ=π/2 which is the angle between the molecular axis and the polarization direction of laser field. Furthermore, in strong field, when the initial vibrational energy is higher than the energy of LICI point, not only the photofragments distributions present obvious quantum interference structures, but also the angular distributions of the photofragments of two cases have opposite oscillatory structure around θ=π/2. This also shows that the GP effect and nonadiabatic effect of LICI are unified in photodissociation processes. The time‐independent Schrödinger equation is solved in two cases including GP and excluding GP for the D2+ molecule. In strong field, when the initial vibrational energy is higher than the energy of LICI point, not only the photofragments distributions present obvious quantum interference structures, but also the angular distribution of photofragments excluding GP is nonvanishing around θ=π/2. We show that the GP effect and nonadiabatic effect of LICI are unified in photodissociation processes.