In conventional electron trapping optical storage phosphor, both short‐ and long‐wavelength light are needed for information write‐in and read‐out, respectively, complicating the optical storage system. Here, a Y3Al2Ga3O12:Pr3+,Eu3+ optical storage phosphor with Pr3+ as an electron donor and Eu3+ as an electron trap is designed, and a single wavelength write‐read scheme is demonstrated, which employs the same blue laser diode (LD) light source for both optical write‐in through two‐photon up‐conversion charging and for read‐out based on photostimulated luminescence (PSL), originated from 4f15d1→4f2 transition of Pr3+ peaked at 315 nm in UV region. A deep electron trap with the mean depth of 1.42 eV and a narrow distribution of 0.3 eV is observed in the presence of Eu3+ in Y3Al2Ga3O12:Pr3+, implying its long‐term storage potential. The write‐in and read‐out experiments are conducted using 450 nm blue LD light with the power density of 1 W cm−2 for write‐in and that with a low power density of 0.02 W cm−2 for read‐out in order to avoid the effect of up‐conversion luminescence on PSL signal. These results will advance the electron trapping optical storage scheme. A novel optical storage scheme with two‐photon write‐in and one‐photon read‐out using a single‐wavelength light source is developed and demonstrated in Y3Al2Ga3O12:Pr3+,Eu3+ storage phosphor. Pr3+ and Eu3+ provide the energy‐level structure for two‐photon write‐in and deep traps for long‐term storage, respectively. This scheme simplifies conventional optical storage systems based on electron‐trapping media.