Abstract: The disclosure discloses a method, apparatus and system for detecting multi-mode electromagnetic acoustic and magnetic flux leakage and a sensor. The method comprises: S102, receiving an operation instruction for detecting an object to be detected, the operation instruction is used for controlling a detection sensor to enter into any one or more of working modes as follows: magnetic flux leakage detection, ultrasonic bulk wave detection, ultrasonic guided wave detection and surface wave detection; S104, controlling the detection sensor to output a corresponding detection signal according to the operation instruction; and S106, detecting the object to be detected on the basis of the detection signal. The technical solution achieves a purpose of using one sensor to realize various detection modes, such as magnetic flux leakage and electromagnetic acoustic modes, reduces complexity and cost of a detection system, and improves detection efficiency.