The temperature of compact antenna test range may vary from 15�� to 25��accompanied by the seasons. The thermal deformation often exceeds the allowed error. Its deformation under the loads of temperature��gravity and reverse force was analyzed with MSC.MARC. For the worst case, the data of the deformed points were used to form a new conic using least-square method. A new generatrix and focus of the reflecting panel that are consistent with the deformed generatrix of the penal were drawn. The results indicate that the regulation of the signal source can fit in with the variation of the focus.