The Yb³⁺/Ho³⁺/Tm³⁺-doped LiTaO₃ polycrystalline materials at various doping mole fractions were prepared using a high-temperature solid-state synthesis method. The X-ray diffraction (XRD) patterns, ultraviolet-visible absorption (UV-Vis) spectra, and upconversion fluorescence emission spectra of Yb³⁺/Ho³⁺ -doped, Yb³⁺/Tm³⁺-doped, and Yb³⁺/Ho³⁺/Tm³⁺-doped LiTaO₃ samples were tested. The XRD results indicate that the doped rare earth ions have not altered the crystal structure of LiTaO₃, suggesting that the rare earth ions entered the lattice by replacing the host ions. The UV absorption edge of the samples shows a redshift followed by a blueshift with increasing mole fractions of Ho³⁺ or Tm³⁺. Under excitation from a 980 nm pump source, upconversion blue light (475 nm), green light (545 nm), and red light (663 nm and 650 nm) were observed in the visible region. The upconversion fluorescence chromaticity can be tailored by varying the mole fractions of Ho³⁺/Tm³⁺ in LiTaO₃. Among the samples, the mole fractions 2.0%Yb³⁺/0.05%Ho³⁺/0.4%Tm³⁺ doped LiTaO₃ polycrystalline specimen exhibits the excellent upconversion output near the standard white light.