In order to study the uniaxial compression characteristics of foamed concrete under freeze-thaw environment, foamed concrete with four kinds of densities (500, 600, 800 and 1 000 kg/m3) were studied with different loading rates (10~100 N/s). Moreover, the pore structure model of foamed concrete under freeze-thaw environment were illustrated by using X-CT. The characteristics and influencing factors of load-displacement curves in the uniaxial compression process were studied, and the relational degrees among the density, freeze-thaw cycles, loading rate and compressive strength of foamed concrete were analyzed utilizing the regression analysis and grey relational theory. The results show that the tangent modulus of load-displacement curve of foamed concrete is reduced greatly and the nonlinear characteristics are enhanced in the uniaxial compression process after freeze-thaw cycles. Besides, the porosity of specimen increases after freeze-thaw cycles, and the discretization of pore size distribution increases. There remains an exponential relationship between compressive strength and density grade of foamed concrete under freeze-thaw environment, and the correlation coefficients are all above 0.9. According to the grey relational theory, the density grade of foamed concrete is more related to the compressive strength than freeze-thaw cycles and loading rate, and the grey relational degrees are all above 0.65.