Abstract: Much more advanced sensors have been used to greatly promote intelligent production with the development of smart fishery. Harsh requirements can be found for the accuracy and biosafety of sensors in practical applications. Wearable electronic devices can be expected to serve as one of the core components with great application prospects. Among them, various sensors can pose an important impact on the design and function of future wearable electronic devices. However, most traditional sensors cannot fully meet the application requirements, due mainly to their rigid characteristics. For example, the invasive detection behavior of rigid sensors can cause fish damage, fish growth and activity, easily leading to data loss. Particularly, the conventional rigid sensors cannot be suitable for the modern fishery, such as large volume and weight, as well as biological incompatibility. Fortunately, flexible wearable sensors have attracted extensive attention and research interest in the fisheries field in recent years, due to the lightweight, portability, high integration, and excellent electrical performance. The scope of sensor applications has also been broadened in fisheries, due to their excellent stretchability and biocompatibility. In this review, a systematic summary was proposed of the materials, processes, energy supply, and communication systems required for the preparation of flexible sensors. Flexible materials were divided into the substrate, function and packaging, materials, according to their functions. These materials were needed to meet the particularity of the fishery application environment, in terms of biocompatibility, air permeability and light transmittance. A comparison was made between the preparation materials and properties of existing flexible sensors. The core process of sensor preparation was introduced, together with better energy supply and communication systems. The emerging nano-friction power generation technology was proposed for fishery flexible electronic equipment. And then, the application of flexible wearable sensing technology was reviewed on fish motion monitoring, water environment monitoring and aquatic product quality detection. The quality detection of aquatic products was divided into biogenic amine, antibacterial drug, and pH detection. Flexible electronic technology was dominated in production cost, measurement accuracy, biocompatibility and application range. At the same time, some recommendations were also given in the future. Fish motion monitoring was necessary to capture the sensing information under sensor application scenarios and biomarker monitoring. The much more flexible sensors can be expected to detect the ammonia nitrogen and dissolved oxygen in the water environment, in order to use environmentally friendly materials during preparation. The challenges and development trends of flexible wearable devices in fishery applications were as follows: 1) To improve the stability and reliability of wearable device sensing under complex conditions, in order to ensure the sensing function of fishery special application environment. 2) To design a micro-sensor system for the multi-parameter integrated detection for better sensing function and application range. 3) To develop reliable self-powered modules for wearable devices, such as nano-friction power generation with excellent biocompatibility and flexibility. 4) To promote the application scenarios of flexible sensors in fisheries, such as fish health management, fish disease prediction and research, and testing medical drugs.