Abstract: Self-developed YQH-100-type of triple stage and axial flow oil-gas mixed pump are taken as the research object and the inclined angle of the blade is changed. Based on the Mixture model of two-phase flow theory, we carried out the numerical simulation of internal flow in oil-gas mixed pump under the five conditions that gas void fractions(GVF) were 0、10%、30%、50%、70%.We researched the distribution of gas and pressure in the impeller, as well as its external characteristics curves. The results show that the blade inclination has a great influence on the head at the pure water conditions. The head of the original model M4 is 8m higher than the worst scheme M1 (the blade tilt -10°).The head of scheme M3 (blade tilt -4°) is 1.4m lower than the original model, and the efficiency is 0.14 percentage points higher than the original model. Under the conditions of small flow rate, the efficiency of the original model is higher.Under different GVF conditions, the pressure increase of scheme M3 (blade tilt -4°) is 14 kPa lower than the original model, and the efficiency is 0.22 percentage points higher than the original model. The inclined angle of the blade can effectively reduce the gathering area of the air masses in the hub side of the blade working faces, make the gas-liquid well-proportioned mixing in the mixed pump, and improve the efficiency of the multiphase pump.The optimum blade tilt range for the oil-gas mixed pump is from -4°to 0°.The results can provide a reference for the design and hydraulic optimization of oil-gas hybrid pump.