The novel compound 3′-(1-benzyl-5-methyl-1H-1,2,3-triazole-4-carbonyl)-4′-(4-bromophenyl)-1′-methyl-2H-spiro [acenaphthylene-1,2′-pyrrolidine]-2-one (BTBANP) is synthesized and characterized by FT-IR/Raman, 1H-NMR, 13C-NMR, fluorescence, UV-Vis, and single-crystal X-ray diffraction. The molecular structure of BTBANP in the ground state is optimized using density functional theory (DFT/B3LYP) method with 6-311G (d, p) basis set and compared with the experimental data. Kurtz powder technique is employed to determine the non-linear optical (NLO) effect of BTBANP and thus the charge delocalization and stability of the compound are discussed. The efficiency of second-harmonic generation (SHG) of BTBANP is 1.53 times more than that of potassium dihydrogen phosphate (KDP). DFT/B3LYP/6-311G (d, p) technique is also utilized to compute NLO, NBO, HOMO-LUMO, global chemical descriptors, and thermodynamic properties at different temperatures. The molecular docking study of BTBANP reveals good inhibitory activity against topoisomerase II and lanosterol 14 α-demethylase enzymes.