Phosphor-conversion light emitting diode (pc-LED), which is fabricated by covering infrared phosphor on the blue light diodes, is an ideal near-infrared (NIR) light source for its advantage of broadband, low power dissipation and easy integration in circuits. And discovering of high efficiency broadband near-infrared emission phosphor for light-emitting diodes is key to this technology. Herein, considering the high thermal stability of silicate matrix, and the similar ion radius of Sc3+ and Cr3+, a chromium doped silicate LiScSi2O6 (LiScSi2O6∶Cr3+) broadband NIR phosphor was prepared in this work by high temperature solid state, which emits a broadband NIR light, peaking at ~850nm, with a full width at half maximum (FWHM) of ~156nm, under the 450nm blue light excitation. The luminescence intensity remains 75.38% of that of at room temperature when the phosphor’s temperature is of 160℃. The luminescence mechanism of Cr3+ in LiScSi2O6 matrix and the model of thermal quenching were also discussed in this paper. A NIR pc-LED was fabricated by combined the phosphor with blue light LED chip, which shows a maximum output NIR power of 436.7mW @ 300mA, and a maximum electron-photon efficiency of 18.3% @ 1mA. This as-fabricated NIR pc-LED is also small in size light and in weight, and can be easily integrated in circuits, which made it have a good application prospect in the domain of night vision and information anti-counterfeiting.