The interaction between the Bi3+ ion and gold is studied using the cluster metal surface model and the density functional method. The geometric and energy characteristics of the interaction between this ion and the gold surface are estimated. Its adsorption is accompanied by the transfer of a core part of the charge onto the gold surface. The electron structure of the Au–Biads3+ system is analyzed. The participation of an adsorbed bismuth ion and the gold atoms adjacent to it in the formation of molecular orbitals in the system is estimated. It is established that the contribution to their formation is provided by the s- and p-orbitals of the bismuth ion and the d-orbitals of gold with its s-orbitals participating only slightly. The interaction with the solvent decreases the transfer of the charge from an adsorbed bismuth ion to gold. It is demonstrated that the hydrolyzability of the bismuth ion decreases after its transition from the electrolyte phase onto the surface.