The physical and hydrogen storage capacity properties of perovskite materials are explored by using computational strategies. In the current scenario, compounds CsD2Nb3H10 (D = Ba, Sr) structural, optoelectronic, stability, mechanical, thermodynamic, and hydrogen storage aspects are investigated and calculated first time. Using the GGA proposed by the PBE method in the CASTEP code, a novel CsD2Nb3H10 (D = Ba, Sr) perovskite substance is investigated. The results show that the CsD2Nb3H10 (D = Ba, Sr) structure is (a=b≠c) tetragonal in phase with a space group of p4/mmm. Based on its electronic properties, CsD2Nb3H10 (D = Ba, Sr) shows bandgap (0.0 eV) metallic behavior. CsD2Nb3H10 (D = Ba, Sr) has volumetric preservation ratios of gravimetric ratios of 5.875 and 6.870 weight percent. Additionally, 69.094 and 75.426 g.H2/L are noted and deemed appropriate for preservation. In order to study light-matter interactions, optical factors are studied. The mechanical attributes of CsD2Nb3H10 (D = Ba, Sr), such as their modulus (B, E, G), mechanical index (6.292, 1.319), compressibility (0.033, 0.023) GPa, and elastic anisotropy (9.995, 0.374), were evaluated and attributed. The density (4.757, 4.452 g/m3), minimum thermal conductivity (0.586, 0.887 W/mK), melting temperature (638.557, 734.643 K), and Debye temperature (147.878, 332.726 K) of the substance are all investigated. Studied analysis demonstrates the potential utility of CsD2Nb3H10 (D = Ba, Sr) for hydrogen storage purposes. Our goal is to conduct experiments on the CsD2Nb3H10 (D = Ba, Sr) combination in the years to come to confirm existing findings and for other energy purposes like photovoltaic catalytic.