Abstract: This study presents a self-developed device that can visually reflect the seepage characteristics of single fracture in rock. Taking the deformation modulus of simulated rock as the main technical index, the additive content of K39 transparent rock material is obtained: accelerator 0.8%, hardening agent 0.6%, defogging agent 0.6%. The roughness of the fracture surface of the original rock is obtained by the accurate re-engraving technique of the second mould turning, which provides technical supports for the study of microscopic seepage flow of fracture. Through the simulation test of the visualization device and the original rock device, the difference coefficient between them is yielded. Furthermore, the modified formula of the seepage flow in original rock is derived. The relevant parameters reflecting rock properties, such as the seepage flow rate and the seepage area, are obtained. The inherent mechanism of the influence of K39 transparent rock material on seepage flow is also clarified. Compared with the seepage test using ELE instrument as research platform, the relative variation coefficient of the difference between the two seepage devices is obtained, which suggests that the visualized seepage device developed in this study is capable in studying the seepage flow in rock fractures. The new device is applied to carry out space multi-angle experiments. Under the influence of multiple factors such as coupling roughness, osmotic pressure, confining pressure, space multi-angle and water self-weight effect, the digital self-identification technology of seepage area provides a foundation for accurately access the relevant parameters of rock seepage characteristics.

Key words: visual seepage device, K39 transparent rock material, accurate reproduction technique of double turn die, digital self-identification technology