Microwave-induced thermoacoustic imaging, as an emerging biomedical imaging technique, combines the high contrast of microwave imaging with the high spatial resolution of ultrasound imaging. Microwave-induced thermoacoustic microscopy, as an important branch of this technology, retains these advantages while possessing the ability to visualize finer tissue characteristics. However, traditional raster scanning mechanisms introduce interference into microwave field distribution due to mechanical motion, thus necessitating multiple signal average to maintain signal-to-noise ratio. Additionally, the idle time during motor movement results in extended single-scan durations, limiting its practical applications. To address these limitations, this work proposes a rapid imaging system based on one-dimensional galvanometer scanning. The system employs a hybrid galvanometer-translation stage architecture and an optimized scanning strategy to minimize microwave field interference, reduce the number of signal averages and shortens the idle time, ultimately achieving more than a tenfold improvement in imaging speed. A specially designed timing control algorithm ensures the precise synchronization of microwave excitation, galvanometer motion, and ultrasound detection, while the reconstruction algorithm suitable for the optimizing scanning method effectively corrects distortions generated in the scanning process. The system performance is assessed through phantom and ex vivo tissue experiments. Resolution tests show hundred-micrometer resolution along all three axes (332 μm × 324 μm × 79 μm), while contrast and depth imaging experiments confirm its ability to clearly distinguish targets with different conductivities, achieving an effective detection depth of at least 10 mm in tissue. Early tumor mimicking experiments further demonstrate the ability of the system to identify lesion boundaries, preliminarily revealing its potential for rapid tumor margin assessment. This approach maintains the imaging quality of microwave-induced thermoacoustic microscopy while enhancing imaging efficiency and system stability, thereby laying a crucial foundation for advancing the technology from laboratory research to clinical applications.