The frequency sweeping interferometer enables high-precision absolute distance measurement over large scales, demonstrating significant research and application value in the field of accelerator alignment, where stringent requirements for measurement accuracy, stability, and environmental adaptability are imposed. A frequency sweeping interferometer system incorporating an HCN (H13C14N) gas absorption cell and an optical switch was developed to achieve multi-channel laser ranging functionality. Since laser trackers are widely used for equipment calibration and installation during accelerator alignment, a spherical collimator compatible with the target mount of laser tracker retroreflectors was designed. To validate system performance, distance measurement accuracy tests were conducted in an experimental environment simulating accelerator alignment. The results indicate that the designed system meets accelerator alignment requirements, with a ranging error not exceeding 30 μm within a 30?m measurement range. This system provides a high-precision, highly adaptable measurement solution for accelerator alignment, offering substantial practical engineering significance.