Impinging stream reactor is widely used in absorption, extraction, and preparation of ultrafine powders due to its good mixing performance. The flow field characteristics of impinging stream reactor are closely related to the mixing performance. Based on impinging stream reactor, the use of a vortex generator and other turbulence elements to improve the flow state of the flow field, enhance the flow performance, and mixing effect of impinging stream reactor needs further research. In this work, the numerical simulation method is used to analyze the flow field characteristics of impinging stream reactor with a cylindrical vortex generator and optimize the size and location parameters of the cylindrical vortex generator. The effects of size and location parameters of cylindrical vortex generators on flow field structure, velocity distribution, turbulence scale, and mixing performance of impinging stream reactor are investigated. The results show that when the diameter of cylindrical vortex generator D is equal to 10 mm, the number of vortices in the impinging stream reactor is the largest, and the influence range of the vortex system is the widest. When the diameter of cylindrical vortex generator D is less than 10 mm, the number of vortices decreases. When the diameter of cylindrical vortex generator D is greater than 10 mm, the influence range of the vortex system decreases. The number of vortexes in the impinging stream reactor decreases and the influence range of the vortex system increases with the increase of the transverse spacing of the column vortex generator. The radial velocity, turbulence scale, and mixing intensity of impinging stream reactor first increase and then decrease with the increase of transverse and longitudinal spacing of cylindrical vortex generators. When the transverse spacing of the cylindrical vortex generator K is equal to 5 mm and the longitudinal spacing of the cylindrical vortex generator J is equal to 70 mm, the mixing effect of the impinging stream reactor is the best.