To simultaneously remove Sr and Cs from a simulated highly active liquid waste, a new ternary solid-state supramolecular adsorbent BnPC6DTXAD-7 (BnPDTX7), based on organic chelating agents 25,27-bis(1-n-propoxy)-calix[4]26,28-crown-6 (BnPC6), 4,4'(5')-di-tert-butyldicyclohexano-18-crown-6 (DT), and polymeric carrier XAD-7 was prepared for the first time. Scanning electronic microscopy and Brunauer-Emmett-Teller analysis demonstrated that BnPDTX7 is a macroporous adsorbent. The adsorption of 20 metals onto BnPDTX7 were studied. Under the optimal adsorption conditions of 3.0 M HNO3, 298 K, and contact time of 60 min, the adsorption capacity toward Cs and Sr were 0.1396 mM/g and 0.1289 mM/g, respectively. The experimental data fit well with the Langmuir model, indicative of the monolayer adsorption mechanism. The thermodynamic parameters, Delta H degrees, Delta G degrees, and Delta S degrees of Cs and Sr adsorption and other valuable chemical engineering data were obtained. BnPDTX7 proves to be a promising adsorbent for the simultaneous removal of Sr and Cs because of its high selectivity, fast kinetics, and high stability.