The piezo-on-insulator (POI) substrate is an emerging piezoelectric single-crystal composite thin film structural material. The POI substrate is composed of a thin layer of piezoelectric single-crystal material (single-crystal lithiumtantalate/lithium niobate), a silicon dioxide layer and a high-resistance silicon substrate. It is prepared by the Smart-Cut process, which can ensure the high uniformity and high-quality batch production of the layer. Through this substrate, the high performance integrated SAW resonators and filters that meet the 5G communication requirements can be designed. The SAW devices based on POI material have excellent characteristics such as high frequency, high Q, low temperature sensitivity and large bandwidth, and at the same time, multiple SAW filters can be integrated on the same chip, which has broad market application prospects. This paper introduces the preparation of POI substrate and the research status at home and abroad, the applications of POI substrate in high performance SAW filter, reviews the key techniques of preparing POI substrate and outlooks the future development trend.