Recently, it is of great significance to explore near-infrared (NIR) phosphor with more application prospects. In this work, a series of Zn2.1 Mg(0.9 − y)GaySnyTa(2 − y)O8:0.003Cr3+ NIR broadband phosphors with high quantum yields and high thermal stability are discovered by uniquely replacing [Mg2+–Ta5+] in Zn2.1Mg0.9Ta2O8 with [Ga3+–Sn4+]. Under 460 nm excitation, Zn2.1Mg0.85Ga0.05Sn0.05Ta1.95O8: 0.003Cr3+ depicts the 600–1100 nm broadband emission with a full-width at half maximum (FWHM) of 210 nm, and the quantum yields can reach 61.2%. Finally, the phosphor was mixed with epoxy resin and encapsulated in a 460 nm blue light emitting diode (LED) chip to convert the NIR LED by phosphor (NIR pc-LED), which was applied in the field of biological nondestructive testing and night vision lighting.