Sr 2 MgSi 2 O 7 host doped with Eu, Dy ions with high brightness and long afterglow was prepared by sintering at high temperature under weak reductive atmosphere. The luminescent properties of this photoluminescent pigment have been systematically studied. The analytical results indicated that the co-doped Eu and Dy ions have little influence on the structure of luminescent materials.That main emission peaks appeared at 469nm and belonging to a broad-emission is ascribed to the 4f 7 →4f 6 5d 1 transition of Eu 2+ in the pigment matrix. The pigment doped only with Eu ions did not have the long afterglow phenomenon. But while co-doped Dy 3+ ions in the pigment matrix, the obvious long afterglow was observed, and its decay process contained fast-decay and slow-decay processes.