Three typical polyester-based particles, polylactic acid (PLA), polyglycolide (PGA) and polybutylene adipate-terephthalate (PBAT), were used as representatives to investigate the degradation law and hydrolysis mechanism of polyester-based particles as temporary plugging agents and evaluate their blocking performance. The results showed that the larger the mass concentration of hydrochloric acid and sodium hydroxide, the higher the temperature, the shorter the complete degradation time, and at the same mass concentration, the degradation in sodium hydroxide solution was faster, and the complete degradation time of PLA, PGA and PBAT in 100 g/L sodium hydroxide solution at 90 ℃ was 15h, 12h and 18d, respectively. The hydrolysis mechanism of polyester particle plugging agent was elucidated with the help of FTIR, XRD and SEM: at the early stage of degradation, the ester group began to hydrolyze, holes appeared on the surface of the particles, and the volume of the particles was slightly reduced; as the degradation proceeded, the hydrolysis preferentially took place in the amorphous zone, the crystallinity increased, the carbonyl index decreased, the hydroxyl index increased, and the holes on the surface of the particles increased and the volume was further reduced; at the late stage of degradation, the hydrolysis of crystalline zone started, the crystallinity decreased, and a large number of polymer molecular chains were broken until the complete degradation. The blocking experiment shows that the larger the mass concentration of the injected polyester particles plugging agent is, the denser the blocking layer is, the stronger the pressure-bearing capacity is, and the pressure-bearing capacity is PLA, PGA, PBAT in descending order.