Hypersonic missiles,unmanned combat aerial vehicles,and other highly maneuverable targets possess maneuverability comparable to that of interceptors,where the interceptor's maneuverability does not exceed 1.2 times that of the target.The terminal acceleration is easily saturated when applying the traditional guidance laws,leading to a significant degradation in interception accuracy.To address this issue,this paper proposes an optimal guidance law for intercepting maneuvering targets with equilibrium maneuverability.By introducing a relative reference frame,an optimal equilibrium compensation strategy that accounts for target maneuvering with dynamic delays is proposed.This strategy overcomes the under-compensation or over-compensation limitations of conventional guidance laws,which rely on presupposed target maneuver pattern.Based on this strategy,terminal constraints for equilibrium interception are formulated,and a two-stage optimal integrated guidance and control method is derived using kinematics in the relative reference frame.In the first stage,the guidance law is designed based on a minimum-distance performance index to rapidly eliminate pointing errors and converge to the equilibrium interception constraint.In the second stage,a quadratic optimal performance index of acceleration is adopted to deal with the effects of target maneuver and inner-loop delay with minimum required acceleration,thereby achieving terminal equilibrium interception of highly maneuverable targets.Comparative simulation results demonstrate that the proposed guidance law significantly reduces the required interception acceleration and improves terminal guidance accuracy compared to existing optimal guidance methods.