The sluggish diffusion and severe lattice distortion effects in high-entropy alloys (HEAs) theoretically impede the movement of radiation-induced point defects, thereby effectively suppressing the formation of larger defect clusters and ultimately enhancing the radiation resistance of materials. Current research on the radiation resistance of HEAs primarily concentrates on the qualitative analysis of the migration behaviors of radiation-induced defects, while the quantitative research on the energy barriers of the migration behavior of point defects is still limited. As a representative HEA system, FeCoCrNiAl-based alloy exhibits exceptional properties, including enhanced ductility, remarkable shear resistance, high tensile yield strength, and excellent oxidation resistance. In this study, FeCoCrNiAl_0.3 alloy is selected as a model material and in-situ observations are conducted by using a 1.25-MV high-voltage electron microscope (HVEM) to systematically investigate the temporal evolution of irradiation-induced defects and precipitates at different temperatures. Based on the statistical data of saturated defect number density and defect growth rates under three irradiation temperatures, two intrinsic parameters of the alloy, i.e. interstitial atom migration energy and vacancy migration energy, are determined to be 1.09 eV and 1.47 eV, respectively. The higher interstitial atomic migration energy may be related to the incorporation of Al that has a smaller threshold energy and exhibits a larger atomic radius difference than the other elements in the alloy. In addition, the morphology and distribution of dislocation loops formed at 723 K and high-energy electron irradiation are characterized in detail, demonstrating the coexistence of perfect dislocation loops and Frank dislocation loops, both of which grow along different crystal planes. No systematic difference in growth process between the two types of loops is observed.