The invention relates to the field of information security, cryptography and encrypted circuits, provides detection on electromagnetic fault injection attack for information security related integrated circuits such as the encrypted circuit, and ensures to respond timely when the attack happens. Therefore, the invention adopts the technical scheme that: the structure of a detector applied to an integrated circuit for detecting electromagnetic fault injection attacks comprises phase inverters A1, A2, A3, A4 and A5, wherein the phase inverters are cascaded to form a ring oscillator, the ring oscillator is buffered through a phase inverter B and outputs a channel of oscillation signals directly input to a combinational logic delay comparative structure Detector1, another channel of oscillation signals is input to another combinational logic delay comparative structure Detector2 through the reverse action of a phase inverter C; and an input signal of each of the two Detectors is output to a clock input end of a trigger of the corresponding Detector through the combinational logic of the Detector. The detection method and the detector are mainly applied to safety design of the integrated circuit.