The invention discloses a gain-and-direction-orientated structure thermal deformation compensation method for a satellite-borne active phase control array antenna. The method comprises the steps of determining structural parameters, material attributes and electromagnetic parameters of the antenna; determining antenna environment thermal load; calculating antenna temperature field distribution under sunshine; determining T/R assembly thermal power consumption; calculating antenna temperature field distribution under the T/R assembly thermal power consumption; performing temperature field superposition and calculating the thermal deformation of the antenna structure; extracting position offset in the array element geometric center; calculating the additional error of the array element space phase; determining the amplitude and phase distribution of array element excitation current; calculating the electrical performance of the antenna; judging whether gain and direction are both satisfied simultaneously or not; and calculating the antenna ideal main beam directed unit vector, the adjusting amount of the array element space phase, and the phase current of the compensated array element excitation current. The compensation method provided by the invention is combined with a phase adjusting method, so that the electrical performance compensation to the deformed satellite-borne active phase control array antenna is realized; the problem of antenna electrical performance degradation caused by structural thermal deformation is solved; and the normal operation of the antenna can be ensured.