Terahertz Gabor in-line digital holographic system has the characteristics of high resolution and compact structure, and it has potential application prospects. The lateral resolution of the system is related to the recording distance, so the research on the effect of recording distance on imaging results in actual imaging system has important application values. By using self-made targets with resolutions of 0.4 mm and 0.6 mm, 2.52 THz Gabor in-line holography imaging experiments with different recording distances are carried out and digital reconstructions are realized by angular-spectrum representation. The reconstructed images are compared and analyzed, and experimental results are close to the theoretical calculation results of the lateral resolution changing with the recording distance.