To achieve the integrated detection of large-aperture segmented optical systems and avoid the manufacture of equal-aperture detection devices, we propose a method of using a sparse aperture to construct an integrated detection device. By measuring the local wavefront at the seams and combining the wavefront reconstruction in the frequency domain, we can finally achieve the co-focus and co-phasing state testing of large-aperture segmented telescopes. Based on simulation analysis, the accuracy of the overall wavefront reconstruction (18 sub-mirrors) of our system is better than 0.01λ (λ stands for wavelength). Regarding the measurement and control accuracy of a single discrete aperture, on the basis of camera alignment, we conduct large-range feedback based on dispersion fringes and achieve precise co-phasing and accuracy verification based on the wide-band method. Ultimately, the closed-loop stabilization accuracy of the system in a non-vibration-isolated environment is better than 0.097λ. For spectral response testing, we use a split-type small-aperture integrating sphere to achieve a spectral splicing measurement of a large-aperture telescope. For an experimental system with an focal ratio of 10, the fluctuation of the light-intensity contrast in each field of view is better than 4%. Due to its small size and light weight, the proposed system can be used not only for integrated inspection in the manufacturing phase, but also for accuracy verification during on-site assembly and system calibration during operation intervals.