In order to explore the effects of temperature and fiber type on uniaxial compression performance of concrete after high temperature, uniaxial compression tests were carried out on normal concrete, polypropylene imitation steel fiber and polypropylene imitation steel fiber-steel fiber reinforced concrete blocks at different temperatures (20, 200, 400 and 600 ℃), and the acoustic emission monitoring system was used to monitor the compression failure process of concrete. According to the test data obtained from acoustic emission and uniaxial compression test, the damage behavior of concrete after high temperature was analyzed. The results show that the compression failure process of concrete is divided into compaction stage, crack propagation stage and instability cracking stage, and the corresponding acoustic emission process is divided into contact stage, slow increase stage and sharp increase stage. The compressive strength loss rate of each sample at different temperatures ranges from 9% to 49%. Through quantitative analysis of acoustic emission signals, it is known that the incorporation of polypropylene imitation steel fiber and polypropylene imitation steel fiber-steel fiber can reduce the initial damage of concrete at 200, 400 and 600 ℃.