Abstract: To investigate the development patterns of mechanical properties and pore structure of geopolymer cold-bonded lightweight aggregate concrete (GCLC), tests on the mechanical properties, microstructure, and pore characteristics of the concrete were conducted. The effects of varying binder-sand ratio, alkali-binder ratio, water-binder ratio, sand content, calcium-silicon ratio, and fiber content on the mechanical properties and pore structure of GCLC were analyzed from both macro- and micro-scales. Furthermore, a correlation model linking the pore structure of GCLC with its macro-mechanical properties was established using fractal theory. The results indicate that the prepared GCLC exhibits lightweight and early-strength characteristics, with compressive strengths exceeding 40 MPa. Similar to lightweight aggregate concrete, the failure mode of GCLC was primarily characterized by aggregate fracture. The matrix of GCLC is relatively dense, with pores and cracks of varying sizes presenting on its surface. The interfacial transition zone between the aggregate and mortar matrix is not pronounced, and there is a phenomenon of cross-interface zone merging. In GCLC, except for macroscopic pores, the porosity ranges from 72% to 90%, which is higher than that of ordinary concrete. The pore structure of GCLC exhibits distinct fractal characteristics in the fractal model based on thermodynamic relationships, with a fractal dimension ranging from 2.689 to 2.843. The mechanical properties and pore structure parameters of GCLC can establish a good linear relationship with the fractal dimension under this model, which provides the experimental and theoretical basis for promoting the engineering application of GCLC.