Ultrasound/photoacoustic dual-modality imaging technology has greatly promoted the clinical application and photoacoustic imaging technology because it integrates the advantages of high-resolution structural imaging of ultrasound and high-contrast functional imaging of photoacoustic imaging. Traditional ultrasound/photoacoustic dual-modality imaging is based mainly on the array probe used in ultrasound imaging to collect photoacoustic signals at the same time. The system has a compact structure and easy operation. However, this kind of equipment utilizes array probes and multi-channel data acquisition system, which makes it expensive. And the imaging quality can be affected by the difference in channel consistency. In this paper, an ultrasound/photoacoustic dual-modality imaging method based on an acoustic scanning galvanometer is proposed. In this system, a single ultrasonic transducer combined with a one-dimensional acoustic scanning galvanometer is used for fast acoustic beam scanning to realize ultrasound/photoacoustic dual-modality imaging. It is a compact, low-cost and fast dual-modality imaging technology. The experimental results show that the effective imaging range of the system is 15.6 mm, and the temporal resolution of ultrasound and photoacoustic imaging are 1.0 and 0.1 s ^–1(B scan), respectively (the temporal resolution of photoacoustic imaging is limited mainly by the laser repetition rate). Based on the proposed technology research, it is helpful to further promote the clinical transformation and popularization of ultrasound/photoacoustic dual-modality imaging. It also provides a low-cost, miniaturized and fast scheme for multimodal imaging technology which is based on ultrasound signal detection.