Tension detection was initially used in safety protection applications, such as crane over-limit detection, elevator over-limit detection, and cable tension detection. With the increasing speed of automated production and the increasing requirements for product quality, accurate tension detection and control have played an increasingly important role in automated production. For example, industries such as steel, nonferrous metals, papermaking, printing, plastic film, and textiles all require accurate and reliable tension detection and control to meet the goals of increasing product processing speed, ensuring stable and high-quality product quality, improving equipment production efficiency, and ultimately realizing intelligent production processes. According to different working principles, tension detection sensors can be divided into several types: capacitive [1], piezomagnetic [2], optical fiber [3], photoelectric [4], surface acoustic wave [5], image [6], and resistance strain, etc. Compared with other technical solutions, tension detection sensors based on the resistance strain principle have the advantages of maturity, stability, and accurate measurement, and are therefore the most widely used at present [7]. The tension detection sensor based on this principle is similar to the common force sensor (or weighing sensor) in structure and principle, but is developed for specific application requirements of tension detection. Therefore, this paper classifies and summarizes the application and design of force sensors in tension detection systems according to the characteristics of the structure, operating conditions and installation methods of the equipment under test in tension detection. Finally, combined with market demand, the importance of tension detection is briefly explained, and the future development direction of force sensors in tension detection is prospected. 1  Tension measurement overview The objects of tension detection are mainly wires and strips, such as yarn, steel rope, cable, film, steel strip and metal foil. In engineering mechanics, this type of constraint formed by soft rope, chain or strip is called flexible constraint, also known as "flexible rope". Its characteristic is that it can only be pulled but not compressed, so when it is under load, only the axial force is not zero. The total internal force of the flexible cable in any cross section is tangent to the curve of the flexible cable in the ideal catenary state, so in general engineering applications, it is collectively referred to as the tension of the flexible cable. In engineering applications, the purpose of measuring the tension of the flexible cable can be roughly divided into two categories: safety monitoring and process (quality) control: 1.1 Safety monitoring Flexible cable structures are widely used in equipment and engineering such as lifting and transportation, oil and mineral exploration. Using wire ropes or ropes as flexible cables can achieve lifting, hoisting and other operations. In this process, the tension control of the wire rope is very critical, and it is necessary to ensure the smooth and accurate transportation of heavy objects and the safe operation of the hoisting equipment. As a typical flexible cable, the wire rope is an ideal device for transmitting tensile force. When it passes through a pulley or a pulley block, the direction and size of the tension can be changed. If the friction of the pulley block is not considered, it can be considered that the tension it is subjected to is in a certain proportional relationship with the load. Since the steel wire rope has such characteristics as a flexible cable device, various lifting machinery must be weighed, overload alarmed and torque alarmed according to laws and regulations, and most of them look for solutions on the steel wire rope. Nowadays, the tension measuring device of the bridge-type force sensor supported at both ends of the fixed pulley of the overhead crane can make the weighing system reach an accuracy of more than 0.1%FS.