The matching between the heterogeneous combination flooding system and the reservoir pore throat is the key factor for realizing the effective injection of the flooding system and dramatically enhancing oil recovery. Based on physical simulation research，a matching relationship chart of the viscoelastic particle flooding agent and reservoir pore throat is established. The 1st to 3rd Submembers of the 2nd Member of Shahejie Formation（Es21-3）in Sheng1 area，Shengtuo Oilfield was preferred as the pilot area，which was the typical post-polymer flooding reservoir. Based on the analysis of the reservoir pore throat characteristics and the established matching relationship chart，the viscoelastic particle flooding agent suitable for the target reservoir in the pilot area was developed，and the efficient heterogeneous combination flooding system suitable for the target reservoir in the pilot area was constructed based on the combination of the polymer and the anionic and nonamphoteric surfactants. The research results show that the heterogeneous combination flooding technology could effectively produce the remaining oil in different types of pores with different pore sizes. The microscopic remaining oil production mechanism of the heterogeneous combination flooding system is proposed. Field application has confirmed that the average injection pressure of injection well was increased by 4.7 MPa，and the average starting pressure was increased by 5.1 MPa.The drag resistance coefficient reached 1.7. The pressure distribution was more uniform，and the displacement was more balanced. As of May 2020，the significant water-cut reduction and production rate increment have been achieved in the pilot area. The comprehensive water-cut of the production well was decreased by 6.3%，and the production rate in the pilot area increased from 39 t/d to 141 t/d. The numerical simulation prediction shows that the oil recovery rate could be further increased by 7.6% after polymer flooding，which has broad prospects for popularization and application.