The wavefront collimation of the large aperture near-infrared interferometer must be controlled strictly. Scanning pentaprism system is introduced to divide the wavefront of the interferometer into a series of sub-wavefronts,and the relative positions of the spot centroid according to every sub-wavefront are recorded on the CCD camera. The normal directions of every sub-wavefront are obtained to reconstruct the tested wavefront,thus the collimation test of the wavefront can be realized. The wavefront in the horizontal direction of the collimation lens of a 210 mm aperture near-infrared interferometer is tested and reconstructed. The effect of system error on the experimental results is analyzed. This method is of low cost and high accuracy,and is particularly applicable to the collimation test of a large aperture near-infrared wavefront.