For exo-atmospheric interception, an adaptive sliding-mode guidance law is presented for accelerating the missile without available aerodynamic force.The missile intercepts the target through fixed axial acceleration and corresponding attitude adjustment.Zero-effort-miss distance is chosen as sliding surface for guidance law derivation.The guidance law comprises the equivalent controller and the uncertainty controller.The equivalent controller is used for eliminating the influence of line-of-sight rotation to reduce miss distance, while the uncertainty controller adapts to the effects of external disturbances such as target maneuver to ensure the rate and stability when reaching the sliding surface.The designed guidance law can be transformed to an attitude control problem and be applied to the exo-atmospheric interceptor with attitude control device.Numerical simulation and analysis are conducted on the derived sliding mode guidance law.The results show that the guidance law has strong robustness and good trajectory characteristics, and can realize target interception effectively.