[en] Highlights: • Bonding the superalkali M₃O to B₄₀ nanocage can form the stable D-A framework. • Linking of superalkali M₃O can effectively narrow the wide band gap of B₄₀ nanocage. • All the composite M₃O-B₄₀ systems can exhibit the large first hyperpolarizability. • All of them can also present the considerably large second hyperpolarizability. Inspired by the fascinating finding of all-boron fullerene B₄₀ (Nat Chem, 2014, 6, 727), we propose a new and effective strategy to construct a series of typical Donor-Acceptor (D-A) frameworks via linking the superalkali M₃O (M = Li and K) unit with the low ionization potential to the B₄₀ nanocage with large electron affinity. By means of the density functional theory computations, we have systematically investigated the structures, electronic properties, the first and second hyperpolarizabilities of these modified B₄₀ nanocage systems. Owing to the formation of a B–O chemical bond, these composite systems (M₃O)_n-B₄₀ (M = Li and K, n = 1 and 2) can possess the considerably large binding energy ranging from 57.0 to 99.8 kcal/mol, indicating their high structure stabilities. Compared with the pristine B₄₀ nanocage, linking the superalkali M₃O can effectively narrow the wide energy gap from the original 2.86 eV to 0.61–1.11 eV, and significantly increase the first and second hyperpolarizabilities to as large as 5.00 × 10⁴–2.46 × 10⁵ au and 1.48 × 10⁷–4.85 × 10⁸ au, respectively, owing to the occurrence of evident electron transfer process in this kind of typical D-A framework. These fascinating findings will be advantageous for promoting the potential applications of the inorganic boron-based nanosystems in the new type of electronic nanodevices and high-performance nonlinear optical materials.