The invention concerns a device (12) for controlling an air flow (F) circulating in a first heat exchanger (4) for a motor vehicle comprising at least two screens (14), the control device (12) being configured to go from a closed configuration in which the screens (14) obstruct the passage of the air flow (F) completely to an open configuration in which the screens (14) are positioned in such a manner as to allow the air flow (F) to pass with a maximum flow rate, and any intermediate configuration. According to the invention, the two screens (14) are adapted to be moved away from one another when the control device (12) goes from the closed configuration to the open configuration and to be moved toward one another when the control device (12) goes from the open configuration to the closed configuration.