Abstract: In this paper, the Gamow-like model is improved by introducing centrifugal potential and electrostatic shielding, and it is used in the study of α decay and proton radioactivity. It is found that our calculations can well reproduce the experimental data. In addition, the modified Gamow-like model is used to predict the proton radioactivity half-lives of 116 proton-rich nuclei and α decay half-lives of seven even-even nuclei with Z=120(^296-308120) and some nuclei on their α decay chains. It will provide important theoretical references for the synthesis and identification of these new nuclides on large scientific devices in the future.