The gas mixer with oxygen-enriched sintering ignition directly affects the ignition effect to the mixing degree of oxygen and air, and ultimately affects the energy saving and consumption reduction of the ignition process. In order to solve the problems that the pressure and flow of the air pipeline and the oxygen pipeline for sintering oxygen-enriched ignition are very different, and the mixing difficulty is high, resulting in the uneven mixing of air and oxygen before the gas mixture enters the burner, and the ignition effect is affected, the method of CFD (computational fluid dynamics) numerical simulation is used to compare the mixing effect of different air and oxygen organizational programs, a high-efficiency mixer of air and oxygen for sintering oxygen-enriched ignition is developed, and the key design parameters of the mixer, such as the injection flow rate, blunt body spacing and blunt body shape are simulated and researched. The results show that, for the special application scenario of oxygen-enriched ignition, the air and oxygen counterflow mixer with blunt body turbulence is the best solution to achieve rapid mixing of O₂ and combustion air. For air-oxygen counterflow mixers with blunt body turbulence, the blunt body shape with a sharp front and a round back, reducing the blunt body spacing and increasing the oxygen flow rate, can effectively improve the oxygen-enriched mixing effect. The field application shows that, the mixing efficiency of the air and oxygen of the developed gas mixer based on blunt turbulence reaches 99.5%, when the shape of the blunt body is sharp front and round back, the oxygen flow velocity is 30 m/s, and the blunt body spacing is 10 mm. The results can provide theoretical and practical guidance for improving the effect of oxygen-enriched ignition.