With the rapid development of robot technology, robot is widely used in daily life. According to different functions, the new generation of robots can be classified into social robots, medical robots, auxiliary robots and humanoid robots. Compared with traditional human-controlled industrial robots, these new-generation robots have the characteristics of close interaction, so it is particularly important to have a safe and accurate interaction system, and the tactile sensor has become the key to achieve this function. Tactile sensors can mimic human skin, and they can express temperature, humidity, force and other senses in a digital way, so that the robot can perform tasks completely and accurately in the process of interacting with the external environment. Flexible tactile sensors have the advantages of flexibility, light weight, versatility and affordability and have possible applications in wearable electronics and artificial intelligence. Therefore, more and more researchers began to study tactile sensors. This review gives an overview of advanced flexible tactile sensors, which focuses on the working principle, new materials and application prospect of three mainstream flexible tactile devices, namely piezoelectric sensor, conductive sensor and resistive tactile sensor. Finally, possible routes, future tendency and new opportunities are presented.