Abstract: Flexible piezoelectric composites, which integrate the mechanical compliance of flexible matrices with the electromechanical energy conversion capability of piezoelectric phases, have attracted increasing attention in recent years. Owing to their excellent deformability and stable piezoelectric response, these materials overcome the inherent limitations of traditional rigid piezoelectric ceramics—such as brittleness and poor adaptability to curved surfaces—thus enabling application in flexible electronic. Consequently, flexible piezoelectric composites have become research hotspots in emerging fields including wearable intelligent systems and health-monitoring technologies. In this review, composite fabrication technologies are categorized into two classes—“liquid-phase” and “solid-phase”—based on material morphological evolution during processing. The historical development, material design strategies, forming techniques, and performance-tuning approaches are summarized. The underlying principles, advantages, and limitations of the two routes are analyzed and compared. Meanwhile, intrinsic correlations among microstructure control, interfacial optimization, and macroscopic property enhancement are elucidated, revealing substantial differences in material compatibility and processing stability. Despite rapid progress, flexible piezoelectric composites still face critical challenges in material systems, scalable manufacturing, and environmental adaptability for practical applications. Looking forward, the integration of green manufacturing and multidisciplinary innovation is expected to serve as the key driving force toward industrialization in areas such as wearable intelligent devices. These developments will provide support for high-performance deployment and promote the sustainable and engineering-oriented advancement of flexible piezoelectric composite technologies.