Electrical characteristics of biological tissues are significant for early diagnosis of tumor tissues. Through detecting the Lorentz force effect of the samples, magneto-acousto-electrical tomography is confirmed to have ability to implement early diagnosis of tumor tissues with recognition of changes in electrical conductivity of organisms. In all previous work on magneto-acousto-electrical tomography, incident ultrasonic pulses are generated from conventional piezoelectric transducers. To avoid the electromagnetic interference to the ultrasonic excitation system, the piezoelectric transducer is required to be placed far away from the detected sample. However, the long distance of ultrasonic propagation between the ultrasonic transducer and the sample limits further clinical research. Firstly, laser-induced ultrasound transducers based on photoacoustic effect are proposed. The optic ultrasonic transducers are polymer-nanomaterial composites formed by carbon black and polydimethylsiloxane, which are promising to generate high-frequency and high-intensity ultrasonic signals through decreasing the thickness of composite films. The acoustic fields generated by optimized laser-induced ultrasound transducers are then characterized, and laser-induced ultrasound transducers are applied in the magneto-acousto-electrical tomography experiment. The results indicate that the output pressure and bandwidth of the ultrasonic signals generated by the laser-induced ultrasound transducers are similar to or better than those generated by the piezoelectric transducers. -6 dB frequency bandwidth and acoustic intensity of the laser-induced ultrasound transducers are measured to be about 7.5 MHz and 2.5 MPa, respectively. Due to the absence of electronics and metal in the laser-induced ultrasound transducers, acoustic sources generated by the laser-induced ultrasound transducers are compatible with magneto-acousto-electrical tomography and insensitive to electromagnetic interference.