The invention discloses a grooved modal neutral-position-returning valve design method based on a gap flow. The grooved modal neutral-position-returning valve design method comprises the following steps that first, the center positions of a neutral-position-returning hole A (4) and a neutral-position-returning hole B (6) in a grooved valve sleeve (2) are determined according to the safe neutral-position-returning position of a control plane; and second, according to the index requirement of the neutral-position-returning speed of an actuator, and through a gap flow formula (please see the specifications for the formula), the diameter and length sizes of a neutral-position-returning control shoulder A (3) and a neutral-position-returning control shoulder B (5) on a valve element (1) are calculated for meeting the safe neutral-position-returning requirement of the actuator. A mode of throttling through a small hole is switched into a mode of throttling through a gap between the shoulders on the valve element and the valve sleeve; by additionally adopting a proportional gain coefficient, the approximate solution in formula derivation and measuring errors of parameters in actual machining are offset; the throttling formula of the gap flow is improved, so that the design accuracy is improved; and the traditional small hole throttling mode is omitted, the anti-pollution capacity of the actuator is improved, and great convenience is brought for subsequent maintenance of the grooved actuator.