To analyze the influence of thermal stress on vibration frequencies, a wing structure finite element model is established using ANSYS. The structural thermal stress distribution and vibration modes are calculated with uniform, non-uniform and non-uniform variable temperature fields. According to the structure deformation of natural vibration, the influence of thermal stresses on natural frequencies is analyzed. The results show that the natural frequencies of the wing structure will decline because of material deterioration in the thermal environment. For some vibration modes whose nodal lines are in the wing surface, the additional heating stress stiffness matrix will take a leading role in the total stiffness matrix, and those natural frequencies will be increased.