As the angles among the optical systems of cameras and star sensors would be changed when a satellite worked on orbits in space environments, this paper proposed a method to measure the angles to improve the orientation precision of cameras. A thermal deformation test for the changed angles of these structures was performed under air pressures and normal temperatures. The digital photogrammetry was used to take the pictures for signed positions on the cameras and star sensors and to calculate coordinates and fit the given planes. By taking a camera as the scale, the angles and their variations were calculated in different working conditions. Results show that the maximum thermal deformation is 227.9″under 4 working conditions and 20 sub-working conditions with different temperature distributions, and the test precision is better than 13.9″. The result is very close to that of the finite element analysis, and the RMS between them is 30.4″. It suggests that the precision of digital photogrammetry could be improved by choosing proper signed positions in photos, eliminating gross errors and taking coordinate conversion with code targets. The method satisfies test requirements for thermal deformation of the satellite structures.