The results of the hydroconversion of high-molecular-mass bitumen components in a mixture with light gasoil after catalytic cracking in the presence of in situ synthesized novel polyfunctional nanocatalysts are presented. The influence of the composition and different modes of introduction of catalyst precursors on the conversion of the high-molecular-mass components and the yield of polycondensation products has been studied. The size, structure, and morphology of in situ forming nanoheterogeneous catalyst particles have been investigated. It has been found that binary nanocatalysts based on Fe1 - x S and MoS2 are the most active in the conversion of asphaltenes and the highest degree of desulfurization is achieved with the use of (Ni3S2 + MoS2)/Al2O3 and (Co9S8 + MoS2)/Al2O3 nanocatalysts.