At present, the research on shape memory alloy (SMA) strip-confined reinforced concrete (RC) columns is mainly based on the macroscopic damage of the samples, while there are few studies on the damage development process and failure mechanism of SMA strip-confined RC columns. In order to study the mechanical properties, damage development process and failure mechanism of RC columns under the constraint of SMA strips, uniaxial compression-acoustic emission tests were carried out on unconstrained, passively-constrained and actively-constrained samples. The analysis was conducted using acoustic emission characteristic parameters, the acoustic emission b value, and acoustic emission event localization. According to the results, following conclusions were made. The maximum peak load and the maximum limit displacement of ARC samples under active constraint of SMA strips were 566.39 kN and 3.75 mm respectively, which were 22.3% and 73.61% higher than those of unconstrained RC samples. The stress-time curves of the acoustic emission characteristic parameters of all samples showed good consistency. With the increase of circumferential constraints, the acoustic emission ringing and energy increased significantly, and the acoustic emission distribution became more concentrated in the third stage; With the increase of circumferential constraints, the decreasing stage of the value b was continuously delayed, and the decreasing range of the value b was obviously increased under active constraint. Under each constraint condition, acoustic emission events gradually developed from both ends of the sample to the middle of the sample. RC samples and PRC samples formed transfixion cracks before 0.8 f_c, while ARC samples formed transfixion cracks after 0.8 f_c. The greater the circumferential constraint, the more obvious the overall improvement of the sample. The experimental results can provide theoretical reference for the study on the damage and failure mechanism of RC columns under different constraints of SMA strips.