The invention provides a reusable launch vehicle landing phase guidance and control law integrated coupling design method. Firstly height deviation and lateral distance deviation are calculated according to RLV landing phase nominal tracks; then an expected flight path angle and a direction angle are obtained by utilizing the Liapunov theorem according to tracking deviation of the nominal tracks; and finally a guidance and control law integrated design method capable of guaranteeing overall stability of a guidance and control loop is put forward by adopting a backstepping design method, and tracking error of the nominal tracks is enabled to possess ISS on disturbance and other uncertainties through combination of the input-state stability (ISS) theory so that influence of the uncertainties can be suppressed by gain adjustment and control. According to the method, the uncertainties and the inter-channel coupling effect affecting an RLV guidance system can be effectively overcome so that performance of the guidance and control system can be enhanced, and overall stability of the guidance and control loop can be guaranteed.