Abstract: To investigate the compressive strength and pore structure characteristics of calcium carbonate whisker and basalt fiber foamed concrete under freeze-thaw environment. X-CT testing and uniaxial compression tests were performed on 600 kg/m³ density whisker-fiber foamed concrete specimens subjected to freeze-thaw cycles. Three-dimensional reconstruction of the pore structure in foamed concrete was achieved using Avizo software. Quantitative analysis of pore structure evolution under freeze-thaw cycles was conducted based on measured porosity, pore size distribution, pore fractal dimension, and other characteristic parameters. Grey correlation theory was employed to explore the correlation between compressive strength and pore structure parameters. The results show that with the increase of freeze-thaw cycles, the porosity and average pore size of foamed concrete increase, the sphericity of pores decreases, the pore size distribution becomes more discrete, and the thickness of pore wall increases, which leads to the decrease of compressive strength. The addition of calcium carbonate whisker and basalt fiber can effectively restrain the influence of freeze-thaw cycle, reduce the porosity and pore diameter of foamed concrete, improve the sphericity of pores, promote the integrity of pore structure and significantly improve its compressive strength; The grey correlation between pore fractal dimension and compressive strength is the highest, ranging from 0.831 to 0.854, indicating that the complexity of pore structure is right.