A cerium oxide (CeO2) nanoparticle is an interesting material for a variety of applications in biotechnology and medicine. CeO2 is the most important rare-earth element and the oxide has attracted much attention due to its promising applications in energy and environmental fields. Different structural characterization technique such as X-ray diffraction and transmission electron microscope has been studied. But the optical characterizations and conductivity of the synthesized CeO2 play a major role. In this paper, the light emission characteristics and thermal conductivity properties of synthesized CeO2 nanoparticles are analyzed by using Elliott resolved photoluminescence and steady state guarded hot method. The proposed method includes three different processes namely Photoluminescence studies of the samples, defect detection and evaluate the thermal conductivity property. The synthesized CeO2 nanoparticles are considered for identifying the structural and light emission characteristics. First, the Elliott resolved photoluminescence method is applied to analyze the light emission characteristics of the CeO2 nanoparticles by identifying the peak intensity at a particular wavelength of light. Then the point defects are identified in the electronic states inside the bandgap. The defect identification and refinement states improve the optical and optoelectronic performance of the CeO2 materials. Finally, the thermal conductivity properties of the prepared CeO2 nanoparticles are analyzed at room temperature by applying a steady state guarded hot measurement method. The thermal conductivity is evaluated with the different steady-state temperatures. The structural and light emission characteristics of the proposed method are analyzed by means of photoluminescence intensity, Commission Internationale de l'Elcairage (CIE) chromaticity coordinates and Correlated color temperature (CCT) values, photoluminescence intensity with defect and without defects, and thermal conductivity.