The crossflow of the displacement medium caused by the reservoir heterogeneity is one of the key issues that restrict the water flooding and polymer flooding in the conglomerate oil reservoirs. According to the heterogeneous distribution of Karamay conglomerate oil reservoir，three visualized sand packed models are designed for the connected，scattered and composite high-permeability areas respectively. Experiments of waterflooding and polymer flooding with high and low mass concentrations are carried out to analyze the crossflow characteristics of waterflooding and polymer flooding under different heterogeneous distributions. Two kinds of profile control and flooding agents，weak gel and particle gel，are used to plug the crossflow channel to explore effective treatment methods for the crossflow of various kinds of heterogeneity. The results show that the connected，scattered and composite distribution among the high-permeability zones in the reservoir are easy to cause crossflow during water flooding. It is difficult to effectively produce the crude oil from the medium and lowpermeability zones as well as the high-permeability zones distributed along non-main stream lines. The crossflow characteristics and treatment methods for the polymer flooding in various heterogeneous models are different. When the high-permeability zone is connected or compositely distributed，crossflow is still obvious for the low-concentration polymer flooding （1 000 mg/L），and the increase of polymer concentration（2 000 mg/L）can expand the swept volume in high-permeability zones distributed along non-main stream lines. The recovery has been increased significantly，but the crude oil in the medium and low-permeability areas has not been effectively produced. Particle gel flooding is the best method for the treatment of crossflow. If the high-permeability area is scattered，the recovery of the low-concentration polymer flooding（1 000 mg/L）is greatly increased. While recovery is difficult to be significantly increased by the high-concentration polymer flooding（2 000 mg/L）. Weak gel flooding is the best way to control crossflow.