Conventional polymers fail to meet the requirements for channeling control and plugging under high temperature and high salinity conditions, creating an urgent demand for more durable materials.Two acrylamide-based preformed particle gels (PPGs): polyelectrolyte-based (DJZ-1) and polyzwitterionic-type (LXLZ-2) were synthesized for enhancing CO₂ plugging efficiency. The swelling behavior of the gel was analyzed under different temperature, salinity and pH conditions using Ritger-Peppas and Yavari-Azizian models. The results indicate that the swelling degrees of DJZ-1 and LXLZ-2 in water are 56 and 18 respectively. With the rise of ionic strength, the swelling degree of DJZ-1 declines remarkably, whereas that of LXLZ-2 stays nearly constant. Changes in pH value only elevate the swelling degree of DJZ-1 and have no impact on LXLZ-2. LXLZ-1 can maintain long-term thermal stability under reservoir conditions at 120 ℃, and both systems can effectively exert the performance of PPG weak gel systems.