The interesting interaction between the laser and the ultrasound field in a liquid medium has been an issue in optical physics research, attracting a large number of experimental and theoretical studies. To facilitate the real-time detection of dynamic ultrasonic signals within liquid environments, experiments involving laser heterodyne and self-mixing interferometry were employed. In order to achieve the purpose of the research, we designed a birefringent-Zeeman dual-frequency laser for the experiments. Through experimental and simulation studies, we elucidated the physical mechanism of ultrasound signals propagating in liquid media and their modulatory impact on laser systems. Meanwhile, the ultrasonic signal frequency measured via the laser self-mixing interferometry approach exhibits an average error of 0.87%, a signal intensity of −14.55dBm, and sensitivity is 28.9 dB higher than laser heterodyne interferometry. These high-precision, high-resolution optical detection methodologies promise to rectify the shortcomings inherent in traditional ultrasonic detection techniques concerning calibration.