<p>Understanding the fractal characteristics of rocks is essential for quantitatively evaluating their pore structures, which is critical for characterizing multiscale heterogeneity, structural complexity, and their implications for fluid transport. This research employed a combination of nuclear magnetic resonance and mercury intrusion porosimetry methods to characterize the pore size distribution and structural heterogeneity of tight sandstones within the study area. By calculating and comprehensively analyzing the multifractal dimensions, multiple linear regression models were developed for adsorption pores and seepage pores. The results indicate that the dominant pore size in tight sandstones ranges from 0.01 to 10 μm, with the pore structure exhibiting pronounced multifractal characteristics across different pore scales. The research identified a correlation between multifractal dimensions and key parameters such as porosity, permeability, and movable fluid saturation. It was shown that fractal dimensions serve as an effective tool for assessing the complexity and heterogeneity of microscopic pore structures in tight sandstone reservoirs. Multifractal dimensions are controlled by various factors; multiple linear regression analyses were conducted for <i>D</i>_A and <i>D</i>_S, with corresponding models developed. It was found that <i>D</i>_A (adsorption pores) is most influenced by porosity, while <i>D</i>_S (seepage pores) is most influenced by average pore size.</p>