Eu3+-doped Sr3Ga2O5Cl2 phosphors were synthesized successfully via a two-step solid-state reaction method. Phase purity and morphology of the phosphor were confirmed by XRD and SEM techniques. In the excitation spectra of Sr3Ga2O5Cl2:Eu3+ phosphor, the broad excitation band centering at 310 nm is due to the combination of charge transfer from Eu3+→O2− and host absorption. And it matches well the emission wavelength from UV LEDs. Sr3Ga2O5Cl2:Eu3+ phosphors show a bright orange–red luminescence under excitation with 301 nm. However, concentration quenching of Eu3+ in Sr3Ga2O5Cl2:Eu3+ occurs at a low content of 0.07 in this work. The quenching mechanism of Sr3Ga2O5Cl2:Eu3+ was discussed in detail on the basis of the experimental results.