The profile control characteristics of modified starch gel system were studied by monolayer homogeneous core model and parallel sand filling tube model. The gel composed of 4% modified starch, 4% acrylamide monomer and gelatinizing control agent in appropriate proportion. The results showed that the injection performance before gelling was good and the residual resistance factor was 834—2548 after gelling, breakthrough pressure gradient was greater than 50 MPa/m as well as the sealing rate was greater than 99%. So water channeling problem could be solved effectively. The influence of three flooding methods on enhanced oil recovery was evaluated based on double-layer inhomogeneous core model. The oil recovery ratio of ternary flooding including 0.3% polyacrylamide, 0.3% sodium alkyl benzene sulfonate and 0.1 g/L NaOH, 0.3% polyacrylamide flooding and water flooding was 20%, 17% and 10%, respectively. Residual oil in high permeability layer would be further produced by modified starch gel system. After gelling, oil in low permeability layer would be produced effectively by ternary flooding system. The recovery ratio increased 37% by combining modified starch gel system and ternary flooding.