Polymer drag reducer is a new type of fracturing fluid additive, which plays an increasingly important role in fracturing process. However, due to the high viscosity characteristic of polymer powder after dissolved in water, especially with the increase of mixing concentration, it is easy to appear a large number of fish eyes and floc, which makes it difficult for traditional technology to achieve rapid and uniform mixing process. Therefore, in order to improve the mixing and application level of polymer drag reducer, realize the rapid and uniform mixing of polymer drag reducer on the fracturing site, and solve the problems of low mixing efficiency, poor uniformity and slow adhesion speed of polymer drag reducer, the continuous mixing system of polymer drag reducer was independently developed. The system is based on process strengthening technology, combined with automatic control and supporting process methods, through real-time monitoring of the whole system, multi-module collaborative control, effectively realize the rapid, uniform and continuous on-site preparation of polymer drag reducer, and form a new solution for continuous mixingand application of polymer drag reducer. After testing, the mixing capacity of the system is not less than 80 m3/h, the maximum mixing concentration is 5%, the concentration error is less than 5%, and the viscosity can reach more than 90% of the stable viscosity in the laboratory within 3 min after mixing. The system of production, performance and control accuracy can meet the needs of the fracturing site, providing technical support for the mixing and application process of polymer drag reducer.