Abstract: The true triaxial hydraulic fracturing experiment serves as a crucial method to investigate the fracture propagation behavior in tight reservoirs. However, current methods for characterizing fractures in experiments faces challenges such as oversimplification, implementation difficulties, and unclear characterization of fracture morphology. To achieve precise and rapid characterization of hydraulic fracture morphology, a three-dimensional fracture reconstruction method based on Radial Basis Function-Partition of Unity Method is established. The hole completion and fracture reconstruction are realized using point cloud data obtained by laser scanning. Meanwhile, the geometric characteristics of the fractures are quantitatively characterized based on the fracture area and fracture roughness. Through a case study of the tight conglomerate reservoir of Baikouquan Formation of Mahu in Xinjiang, the fracture propagation law under the conditions of different gravel diameters and arrangements, horizontal stress difference, cluster spacing and cluster number, and pump rate are analyzed. The results indicate that the three-dimensional fracture reconstruction method based on the Radial Basis Function-Partition of Unity Method demonstrates good reconstruction accuracy and enables fast and intuitive characterization of hydraulic fracture morphology in tight reservoirs. This study provides a novel digital method for evaluating hydraulic fracturing and analyzing fracture propagation mechanism.