White LEDs have a broad application prospects and market demand, while the red phosphor play a big impact on the color temperature and color rendering index of the modulated white light. In this paper, a series of Li ₂Gd _4-xSm _x(MoO ₄) ₇( x=0.01-0.13) phosphors were prepared by high temperature solid phase method. The successful doping of Sm ³⁺into Li ₂Gd ₄(MoO ₄) ₇was confirmed by X-ray diffractometry (XRD) and did not result in any change in crystal structure. The samples were detected by scanning electron microscope (SEM) as irregular blocky structures with particle size less than 20μm. The presence of Li, Gd, Mo, O and Sm elements in the phosphor was confirmed by energy dispersive X-ray spectroscopy (EDS). X-ray photoelectron spectroscopy (XPS) studies showed that the activator was successfully doped into materials. Under 406 nm excitation, the emission peaks of the sample are located at 563, 598, 645 and 706nm respectively, which are caused by the 4 f-4 ftransition of Sm ³⁺and the strongest emission peak comes from ⁴G _5/2→ ⁶H _9/2transition. It was found that optimal concentration of Sm ³⁺is 0.07. With the increase of Sm ³⁺concentration, the fluorescence lifetime decreases gradually. The temperature-dependent emission of phosphor was also studied. The emission intensity at 473 K was still 79% of that at 298 K, indicating that the sample had excellent heat resistance. The CIE chromaticity diagram shows the luminescence of the prepared phosphor is located in the orange-red region and the color purity is high (99%). Moreover, a white LED is manufactured using the optical doped phosphor, which has CIE coordinates of (0.3788, 0.3134) and is located in the circle of white light. Research shows that Li ₂Gd ₄(MoO ₄) ₇: Sm ³⁺phosphor is a promising orange-red phosphor for white LEDs.