Piezoelectric materials are widely used in sensors and actuators due to their unique electromechanical coupling capability. However, the tradeoff between flexibility and high piezoelectric performance restrains their application into flexible electronic technology, which is an important underpinning for the future intelligent technology. In this review, we summarized the flexible piezoelectric materials currently available and their design and preparation strategies. Also, the application of flexible piezoelectric materials in pressure sensing, energy harvesting and biomedicine was outlined. Finally, we gave the challenges and perspectives of developing the flexible piezoelectric materials.