Dy3+-activated Na3YSi2O7 phosphors have been prepared via a solid-state reaction technique and may be used as a component of white light-emitting diodes. X-ray diffraction analysis demonstrates the single-phase formation and the substitution of activator ions for Na3YSi2O7:Dy3+ materials. The emission of Dy3+ in different Y3+ lattice sites exhibits blue (4F9/2→6H15/2) and yellow (4F9/2→6H13/2) lights, which function together to generate white light. The optimum doping concentration is 3 mol% and energy transfer between Dy3+ ions has been validated to be a resonant type via an electric dipole–dipole mechanism. The temperature-dependent luminescent properties from 25°C to 400°C are studied, and the blue emission increases as a function of the temperature. This interesting phenomenon is proposed to be the result of the model in the configurational coordination diagram. The present investigation reveals the potential application for Na3YSi2O7:Dy3+ system in solid-state lighting.