Photoacoustic conversion refers to the process of using photoacoustic effect to produce sound. High frequency and wide band ultrasonic signals can be generated by stimulating photoacoustic materials with pulsed light. Metal nanostructures generate localized surface plasmon resonance and therefore have high optical absorption and controllability, so that they can be used as important photoacoustic conversion materials and can be applied to biomedical imaging and other fields. In this paper, the mechanisms and principles of the photoacoustic conversion are firstly introduced. Then the research and application progresses of photoacoustic conversion of metal nanostructures such as gold nanorods, gold nanodisks, and gold nanoarrays are summarized. Finally, the possible future development directions of metal photoacoustic nanomaterials are prospected.