The invention concerns a method for regulating flow of powder in a device including an injector (2) sucking the powder (6) from a container (4) by Venturi effect, the injector (2) receiving at its intake an injection air flow (Dai), and, proximate to an outlet, a dilution air flow (Dad). Two proportional electromagnetic valves (12, 13) are arranged respectively on the injection air intake (7) and on the dilution air intake (8). Said electromagnetic valves (12, 13) are controlled by an adjusting module (11) which receives a powder flow setpoint (Dp) and which determines injection air (Dai) and dilution air (Dad) flow rates taking into account stored coefficients. (A, B) and a minimum total air flow (Dam) to be observed, based on the formula Dp/A.Dai B.Dad. The invention is useful for feeding a spraying appliance (10) with paint or any other powder coating product.