Based on the clinical requirements of precision diagnosis and treatment, this paper proposes magnetically mediated thermoacoustic coupling imaging technology with magnetic nanoparticles (MNPs) in view of the limitations of existing molecular imaging technology in clinical application, such as insufficient sensitivity, shallow detection depth, or high cost. The electromagnetic and acoustic response characteristics and magnetically mediated thermoacoustic effect of magnetic nanoparticles were analyzed, the characteristics of magnetically mediated thermoacoustic signal under pulsed magnetic field excitation were studied, and the distribution image of magnetic nanoparticles was reconstructed by using the extracted sound pressure data. The signal-to-noise ratio of thermoacoustic signal was improved through narrow pulse excitation and ultrasonic signal detection technology matching with excitation parameters. The multi-channel magnetically mediated thermoacoustic real-time imaging system for magnetic nanoparticles was designed and developed, and a series of experiments were carried out to realize the imaging of magnetic nanoparticles with high resolution, large depth and high signal-to-noise ratio.