Abstract: During the service of spaceborne phased arrays, solar radiation and the self-heating of T/R components induce deformation in the array surface, which would degrade the antenna's electrical performance. To address this issue, a method of optimizing the placement and reducing the number of temperature sensors is proposed, thereby streamlining the sensor layout used for deformation inversion. Subsequently, the phase compensation method is used to achieve electrical compensation through a "temperature-deformation-electrical compensation" process. Simulation and experimental results demonstrate that the proposed method needs fewer sensors, and achieves a sparsification rate of over 54% during both heating and cooling working processes. Under the phase shifter accuracy of 5.625°, the gain and 3 dB beamwidth are restored to previous levels, and the main beam direction deviation decreases from 0.5° to 0.11° after the compensation. This proposed method demonstrates excellent engineering practicality.