High-entropy ceramic is a hot topic in the recent study of ceramic materials. High-entropy ceramics with excellent properties is the development trend of ceramic materials. In this research, high-entropy transparent ceramic was synthesized by combustion method combined with vacuum sintering. The result indicates that the mean grain size of high-entropy (La_0.2Nd_0.2Sm_0.2Gd_0.2Er_0.2)₂Zr₂O₇ powder is about 8 nm. And the high-entropy powder is disordered deficient fluorite structure. The final transparent ceramics sintered in vacuum furnace at different temperatures exhibit ordered pyrochlore structure. Sintering temperature has little effect on the transmittance of ceramics. And the in-line transmittance of as-prepared transparent ceramic can reach 74% at 1730 nm. There are many absorption peaks in the transmittance spectrum. With the increase of sintering temperature, the body density and grain size of ceramics increase, but the HV hardnesses decrease.