Abstract Flexible zinc‐air batteries (FZABs) have emerged as a promising alternative to lithium‐ion batteries in flexible electronic devices due to the advantages of excellent mechanical properties, high energy density, and notable safety. However, the unclear causes of performance degradation and failure mechanisms of FZABs significantly impede their commercialization. Therefore, extensive research is needed to fully reveal the factors and mechanisms responsible for the performance decline of FZABs. In this review, the failure mechanisms of FZABs' key components, including the Zn anode, solid electrolyte, catalyst air cathode, and electrolyte/electrode interface are analyzed and discussed. To promote further research and development of FZABs, a series of challenges and corresponding strategies are summarized and analyzed. Finally, the future development of FZABs is envisioned. This paper aims to comprehensively elucidate the failure mechanisms of FZABs, guide the development of high‐performance FZABs, and thus promote their commercialization.