This paper researches the seepage characteristics and oil displacement effect of polymer solution and weak-base ternary compound system, taking the reservoir geology and fluid from Daqing Oilfield as research object, taking injectionpressure and oil recovery as the evaluation indexes. Results show that, under the condition of the same oil displacement agent viscosity and slug size, the oil recovery increment of weak-base ASP flooding is larger than that of polymer flooding. Because there are emulsification and Jamin effect during weak-base ASP flooding, which can increase seepage resistance and injection-pressure, and its oil sweep efficiency is also higher. Compared with ternary compound system with scaleremoval water, there are carbonate micro particles in the sewage ternary compound system, which can be detained in porous media. This can increase seepage resistance and cause fluid diversion effect, which eventually leads to a large increase in oil recovery. Compared with constant-speed experiment, it is early for constantpressure experiment to adopt peak-pressure, which accelerates the forward speed of agent in the core high permeability layer and shortens the breakthrough time. As a result, the sweep efficiency and oil displacement efficiency of constantpressure experiment is lower.