The invention provides a numerical simulation method for a heterogeneous oil combination flooding system. The method comprises the steps of solving a water phase pressure equation and an oil phase pressure equation; solving a phase saturability equation and a mass conservation equation of all components, and calculating the pre-crosslinked gel particle concentration under the current time step; calculating the pre-crosslinked gel particle residual resistance factor under the current time step in an interpolation mode according to a pre-crosslinked gel particle residual resistance factor curve; calculating the viscosity of pre-crosslinked gel particle suspension liquid; correcting the fluidity coefficient of the Darcy law, calculating water phase flowing speed according to the Darcy law, and carrying out phase pressure equation calculation of the next time step until the heterogeneous combination flooding simulation time is over. By means of the numerical simulation method for the heterogeneous oil combination flooding system, a mathematic model describing heterogeneous combination flooding blocking profile control and migration profile controlling and flooding, and the numerical simulation method effectively representing the pre-crosslinked gel particle displacement mechanism is provided.