The invention relates to the technical field of underground oil reservoir treatment, in particular to an adjustable low-frequency sound wave oil field treatment system. The system comprises a wellhead control device, an underground low-frequency generation device and a transmission device, the transmission device is connected with the wellhead control device and the underground low-frequency generation device and comprises a wellhead three-way structure which comprises a vertical two-opening pipeline and a horizontal branch pipeline, an underwater acoustic transducer is arranged at an inlet of the horizontal branch pipeline which is positioned in the middle of the vertical two-opening pipeline, and the underwater acoustic transducer is connected with the underground low-frequency generation device through an acoustic frequency transmission line. The wellhead control device comprises a central controller, a rectifier, an inverter and a drive circuit, the underground low-frequency generation device comprises a signal processor, an acoustic parametric array, a motor control module and a two-axis platform. The signal processor is connected with the acoustic parametric array and the motor control module, and the two-axis platform is connected with the motor control module, so that oil production efficiency is improved.