This paper presents a method for modeling heterogeneous rock masses using the Discrete Element Method (DEM) and the Weibull distribution to describe the heterogeneity of rock hydraulics. The developed program overcomes the limitation of the Universal Distinct Element Code (UDEC) software, which cannot handle more than 50 parameter groups. The study proposes a method for parameter assignment of heterogeneous rocks and estimating the initial flow rate value of heterogeneous models. The influence of block homogeneity, hydraulic aperture homogeneity, and stress on seepage characteristics is analyzed. The results show that under zero stress conditions, the flow rate is positively correlated with \( N^{0.5} \) and exhibits a strong linear relationship, with a correlation coefficient greater than 0.9996. The linear relationship is enhanced with the increase in the shape parameter \( m \). The relationship between the flow rate and \( m \) is logarithmic, with a correlation coefficient greater than 0.9654. The relationship between the flow rate and axial pressure is described by a quadratic polynomial, with a correlation coefficient greater than 99.72%. The relationship between the flow rate and confining pressure is described by a cubic polynomial, with a correlation coefficient greater than 99.98%. The equivalent hydraulic aperture (EHA) is found to be linearly dependent on confining pressure and quadratically dependent on axial pressure, with a logarithmic relationship between EHA and \( m \). The study provides a comprehensive understanding of the seepage characteristics of heterogeneous rock masses under various stress conditions.This paper presents a method for modeling heterogeneous rock masses using the Discrete Element Method (DEM) and the Weibull distribution to describe the heterogeneity of rock hydraulics. The developed program overcomes the limitation of the Universal Distinct Element Code (UDEC) software, which cannot handle more than 50 parameter groups. The study proposes a method for parameter assignment of heterogeneous rocks and estimating the initial flow rate value of heterogeneous models. The influence of block homogeneity, hydraulic aperture homogeneity, and stress on seepage characteristics is analyzed. The results show that under zero stress conditions, the flow rate is positively correlated with \( N^{0.5} \) and exhibits a strong linear relationship, with a correlation coefficient greater than 0.9996. The linear relationship is enhanced with the increase in the shape parameter \( m \). The relationship between the flow rate and \( m \) is logarithmic, with a correlation coefficient greater than 0.9654. The relationship between the flow rate and axial pressure is described by a quadratic polynomial, with a correlation coefficient greater than 99.72%. The relationship between the flow rate and confining pressure is described by a cubic polynomial, with a correlation coefficient greater than 99.98%. The equivalent hydraulic aperture (EHA) is found to be linearly dependent on confining pressure and quadratically dependent on axial pressure, with a logarithmic relationship between EHA and \( m \). The study provides a comprehensive understanding of the seepage characteristics of heterogeneous rock masses under various stress conditions.