Based on the principle of microscopic reversibility, this article proposes a trajectory model for the multichannel process of direct four-body recombination of two positively charged and two negatively singly charged ions. The trajectory calculations used a potential energy surface that quantitatively describes the inverse process of collision-induced dissociation of the corresponding diatomic molecules. Key interaction characteristics, such as the recombination probability as a function of collision energy and the ratios of recombination probabilities for individual channels, were obtained. It was found that in all channels in which stable diatomic molecules are formed, their vibrational energy shows an inverted population of energy levels, while the distribution of rotational energy has the form of an equilibrium Boltzmann distribution.