On the basis of a kind of zinc phosphate oxynitride glass matrix with a broadband blue light, a series of manganese single‐doped glasses were obtained. A broader red emission with the higher intensity belonging to the Mn2+ ion was observed in this glass matrix. The mechanism of the emission from Mn2+ ions was clarified through Mn3+ as an “energy acquisition probe” to replace complex dynamic luminescence discussion, which was a fit explanation for the differences in luminescence behavior of Mn ions in prepared glasses at different degrees of redox. The research results indicated that the prepared manganese‐doped glass was a potential candidate as phosphor‐converted white‐light‐emitting diodes. An encapsulated white‐light‐emitting diode device based on this glass with 276 nm ultraviolet chip was achieved. It showed the CIE values of (0.33, 0.35), high CRI (Ra = 86), and low color temperature (5228 K).