Extensive research has shown that expansive agents can reduce engineering cracks of concrete, while temperature and creep significantly affect the ability of the expansive agent to compensate shrinkage of concrete. In order to study the expansion and creep of concrete mixed with expansive agents under variable temperature, Series of parameters of concrete mixed with MgO expansive agent (MEA) and CaO-calcium sulfoaluminate expansive agent (CEA) were tested by temperature stress testing machine (TSTM), and the elastic modulus, expansion and creep were calculated according to the maturity theory. The results showed that CEA had a larger free expansion but smaller constrained expansion compared to MEA, and the expansion energy of CEA almost completely released within 36 h of the temperature-rise stage. MEA had a smaller compressive stress creep in the temperature-rise stage and larger tensile stress creep in the cooling stage, which was beneficial to resistance to cracking. The proposed expansion kinetics model showed a remarkable level of consistency with the test results and held significant importance in guiding the application of MEA in practical engineering.