The Ca2SiO4:Dy3+ phosphor was synthesized by the high temperature solid-state reaction method in air. The emission spectrum of Ca2SiO4:Dy3+ phosphor shows several bands at 486, 575, and 665 nm under the 365-nm excitation. The effects of Li+, Na+, and K+ on the emission spectrum of Ca2SiO4:Dy3+ phosphor were studied. The results show that the emission spectrum intensity is greatly influenced by Li+, Na+, and K+. The charge compensation concentration corresponding to the maximum emission intensity is different with different charge compensations.