Palladium (Pd), as an important material in various industrial fields with an increasing demand but limited reserve, needs to be obtained from new kinds of sources. In spent nuclear fuel, the Pd with industrially acceptable low radioactivity reaches an amount of 1.28 kg/ton, which is necessary and feasible to be separated and fully utilized. In this study, potassium cadmium ferrocyanide (KCdFC) was synthesized by gelation method. This adsorbent shows high selectivity for Pd and a high saturated adsorption capacity of 126.32 mg/g. After absorbing 1000 kGy dose of γ-rays, the microstructure and the characteristic functional groups of KCdFC remained unchanged, and the adsorption capacity decreased by only 6.4%, exhibiting excellent radiation stability. By using in-pore crystallization method through rotary evaporation, the silica-based KCdFC adsorbent (KCdFC/SiO2) was successfully produced to achieve the feasibility of industrial application. In simulated high level liquid waste (HLLW), KCdFC/ SiO2 showed an uptake rate of more than 95% for Pd, while the value for other competitive elements was less than 10%. The KCdFC/SiO2 adsorbent with high efficiency and radiation stability provides a feasible method to improve the utilization rate of Pd resources in spent fuel.