The mechanoluminescence (ML) materials Sr2SiO4∶Eu, Dy were prepared by high temperature solid-state reaction method. The luminescent and mechanoluminescent properties of Sr2SiO4∶Eu, Dy with differentDy3+ concentrations have been investigated. The results showed that α and β phases of Sr2SiO4 co-existed for the low doped content of Dy3+. When the doped Dy3+ concentration increased, the β phase transited into α phase gradually. Since the Eu2+ ions occupied different Sr sites, the samples presented both blue emission at 486 nm (Sr1) and green emission at 530 nm (Sr2). However, the mechanoluminescent (ML) and afterglow spectra were consistent in the emission at 530 nm, which indicated that both emissions originated from Eu2+ transition located at Sr2 sites. Comparing thechange of mechanoluminescent (ML) and afterglow intensity, we can conclude that the changes of mechanoluminescence performance are not only related to the traps but also related to its structural. At the same time, the ML intensity of Sr2SiO4∶Eu, Dy increased with the increase of mechanical load and the ML images of Sr2SiO4∶Eu, Dy can be observed by naked eyes, which suggested this phosphor can be applied as potential sensors to detect stress. Furthermore, combined with afterglow, thermoluminescence and ML properties, it can be inferred thatthe origin of ML is piezoelectricity-induced electroluminescence, that is, piezoelectricity impelled the trapped electrons from the traps and produce ML.