The invention discloses a maintenance decision-making method for an aircraft bleed air pressure regulating valve. The method comprises: step 1, initializing parameters; step 2, counting the use history of each component, and analyzing a reliability sample; step 3, analyzing a function relationship among various maintenance costs of the aircraft bleed air pressure regulating valve; step 4, evaluating the reliability distribution of the aircraft bleed air pressure adjusting valve; step 5, calculating the maintenance cost rate and availability of the aircraft; step 6, establishing a multi-objective planning model; step 7, converting the multi-objective planning model into an unconstrained optimization problem; step 8, carrying out iterative solution on the unconstrained optimization problem;step 9, judging whether the iterative computation meets an end condition or not, if so, turning to step 12, and otherwise, turning to step 10; step 10, updating a Lagrangian multiplier penalty factor;step 11, updating the multiplier parameters, and turning to step 8; and step 12, analyzing the rationality of the maintenance decision of the aircraft bleed air pressure regulating valve.