In order to study the damage evolution of recycled concrete under high temperature of carbonation, the experiments were conducted on C30 recycled concrete (0%, 50% and 100% mass fraction replacement) under different temperature gradients (room temperature 20 ℃, medium and low temperature 200 ℃, and medium and high temperature 400 ℃) after carbonation with axial compression tests and simultaneous acquisition of acoustic emission (AE) signals, and the damage model of recycled concrete was established based on the analysis of acoustic emission characteristic parameters. The test results show that, analyzed AE damage location, cumulative impact count and energy count, dynamic monitoring of recycled concrete (RC) axial compression failure was realized from initial damage to micro fracture evolution, then to macro fracture propagation and finally to specimen failure; for RC specimens with different replacement ratio of coarse aggregate for comparison, the dense and concentrated location of damage points was the same as the failure position during loading process. Furthermore, RC with three different replacement ratios of coarse aggregate have the initial damage increases, the AE parameters increase and the stress decreases with the increase of temperature gradient. As a result, the concrete damage model based on AE cumulative impact count can be used to analyze the damage evolution law of RC after carbonization at high temperature under axial compression.