The invention relates to heterogeneous systems for profile control/oil displacement of oilfield injection wells and discloses a heterogeneous system for oil displacement or profile control of heterogeneous reservoirs and a preparation method for the heterogeneous system. The heterogeneous system consists of a continuous phase and a disperse phase, wherein the continuous phase is an aqueous solution of partially hydrolyzed polyacrylamide, an aqueous solution of a partially hydrolyzed polyacrylamide emulsion or a flow gel system prepared from partially hydrolyzed polyacrylamide; and the disperse phase is expandable pre-crosslinked gel polymer particles. According to the heterogeneous system, the continuous phase is responsible for carrying the disperse phase and carrying out mobility control in strata, and the disperse phase blocks high-permeability strata through the expansion of the particles, so that the fluid diversion capability is strengthened, and the profile control oil displacement effect is better exerted; according to the system, the solution can be prepared by directly adopting oilfield reinjection water, so that water resources can be conserved, and the environmental pollution caused by oilfield produced water is reduced; the dissolving is convenient, and the construction is simple; and the system can be applied to the profile control/ oil displacement of the oilfield injection wells at a high-water-cut stage.