Abstract: As an increasing widely used non-destructive testing technology, acoustic emission technology can be used as an important means for breakthroughs in the research of recycled concrete damage. In order to study the acoustic emission characteristics and Kaiser effect of recycled concrete, the change of the acoustic emission energy of recycled concrete with different replacement rates of recycled coarse aggregate during uniaxial compression was used to predict the development of cracks, and the dominant frequency was analyzed with the replacement rate. The relationship between the changes and the cyclic loading and unloading of recycled concrete with different substitution rates was carried out to verify the existence of the Kaiser effect. The test results show that the Kaiser effect exists in recycled concrete, but unlike ordinary concrete, there is no lower stress limit for the Kaiser effect of recycled concrete, but the upper stress limit is increased to some extent.