The technology of microwave-induced thermo-acoustic tomography that transmits electromagnetic wave pulses to the object and makes it absorb energy, can cause a rapid temperature rise in it. At the same time, a pressure wave will be generated instantaneouly, corresponding to generating an ultrasonic signal which can be detected by an ultrasonic sensor. After the ultrasonic signal is sampled and an image reconstructed, the image can reflect the characteristics of the electromagnetic energy absorbed by the object. The method combines a microwave imaging of high contrast and high resolution ultrasound imaging characteristics, hence verifies theoretically the feasibility of the thermo-acoustic imaging techniques for early breast cancer detection. In this study, we use S-band microwave pulse radiation source to radiate the biological tissue, and also make use of the circling mechanical motion systems to scan the tissue. In order to verify the imaging performance of the simulation experiments, we use both tumors, body and actual biological tissue as the samples of the experiments. The imaging reconstruction and comparative analysis can verify that the experimental system detects and distinguishes the tumor phantoms and the real biological tissue effectively. Results of the performance of high-resolution images and high contrast by the methods can provide further theoretical support for early detecting of breast cancer.