The invention discloses a magnetic, acoustic and electric imaging system based on low-frequency mechanical vibration excitation. The magnetic, acoustic and electric imaging system comprises a water trough, a mechanical vibration excitation source, a control and processing device and a collecting device. The control and processing device outputs driving signals to drive the mechanical vibration excitation source to generate low-frequency mechanical vibration, and the mechanical vibration excitation source controls an imaging body in the water trough to carry out corresponding low-frequency vibration in a formed static magnetic field. The collecting device collects electric signals and ultrasonic signals generated by the imaging body and transmits the electric signals and the ultrasonic signals to the control and processing device. The control and processing device carries out imaging processing on the electric signals and calculates current intensity information according to the electric signals and the ultrasonic signals. Existing acoustic radial force excitation is changed to mechanical vibrator excitation, and low-frequency vibration is formed in the imaging body, so that the purpose of exciting the imaging body in a low-frequency mode is achieved, and the problem that an existing acoustic radial force excitation mode based on an ultrasonic probe is not suitable for low-frequency vibration magnetic, acoustic and electric imaging systems is solved.