Given the increasing hazard of ionizing radiation, it is critical to investigate the photon attenuation properties of Li7-xLa3Zr2-xTaxO12 (LLZTO) ceramics to optimize their application in radiation shielding. The solid-phase reaction method was used to prepared LLZTO ceramics of various densities. At the Ta doping of 0.6, the prepared LLZTO ceramic possesses a stable cubic phase structure, particle size uniformly distributed and tightly packed, and a relative density as high as 89.7%. Subsequently, the Phy-X program and Monte Carlo simulation evaluated the photon attenuation performance of the LLZTO ceramics. The addition of Ta increases the density and effective atomic number of LLZTO ceramics, the number and probability of extra-nuclear electrons that can collide with the incident photons in unit path length and the photon shielding capability of the ceramics. LLZTO ceramic with 0.6 Ta doping has an average specific lead equivalent of 0.524 and 0.322 mmPb/mm in medical diagnostic therapy and fast neutron nuclear applications, respectively, and can achieve saturation shielding of incident X-rays and fast neutrons with thicknesses of only 0.2 and 10 cm, respectively. Furthermore, the mechanism of the LLZTO ceramic shielding performance was analyzed from the perspective of photon-matter interactions. LLZTO ceramics have considerable photon attenuation ability in the wide energy range of 10- 3-103 MeV and are potential photon-absorbing shields.