The invention discloses a flying wing aircraft yaw control device based on an active flow control technology. The flying wing aircraft yaw control device comprises a ducted fan, an air inlet channel, an upper surface front end air outlet, an upper surface rear end air outlet, a rear air outlet, a lower surface front end air outlet, a lower surface rear end air outlet, another rear air outlet and airflow guiding pieces. The ducted fan and the air inlet channel are fixed together through screws, and the airflow guiding pieces are arranged at the front and the rear ends of the interior of the flying wing aircraft yaw control device. Yaw control over a flying wing aircraft can be effectively achieved through different air-blowing motivation forms. The flying wing aircraft yaw control device has the advantages that a traditional flying wing aircraft yaw control component, namely a cracking type drag rudder, can be replaced, rudder-free yaw control is achieved, and the active flow control device is higher in response speed, simpler in structure, lower in weight and convenient to install and maintain.