As a minimally invasive surgery, microwave ablation (MWA) has been widely used in tumor treatment. However, the electromagnetic properties of tissue will change with temperature during operation, which may lead to unstable performance or even failure of the antenna. In this paper, we preliminarily verified the feasibility of improving the stability of microwave ablation antenna by adjusting the frequency. Experimental results show that the ablation zone is change form 16 mm × 40 mm to 20 mm × 35 mm with frequency adjustment, showing larger and more localized ablation zone. In addition, the $S_{11}$ keeps remaining lower than −10dB during the operation, while the $S_{11}$ at 2.45 GHz without frequency adjustment is expanded to −8.5dB at the end of the experiment.