Based on C30 recycled concrete (mass fraction replace 0%, 100%) under different temperature gradients(room temperature 20℃, medium and low temperature 200℃ and medium and high temperature 400℃) through carbonization, the acoustic emission characteristic parameters were used to describe the damage evolution law of recycled concrete during axial compression. The test results show that through the analysis of AE damage location, cumulative hit count and energy count, the dynamic monitoring of the whole process of axial compression failure of recycled concrete from cumulative damage to micro-cracks, and then to macro-crack propagation, and finally to specimen failure can be realized. For recycled concrete and ordinary concrete specimens used for comparison, the concentrated location of damage points in the loading process is consistent with the final failure location of specimens；With the increase of temperature gradient, the initial damage of ordinary concrete and recycled concrete increases, the acoustic emission parameters increase and the stress decreases; The concrete damage model based on acoustic emission cumulative hit count can be used to analyze the damage evolution law of carbonated high temperature recycled concrete under axial compression.