The embodiment of the invention discloses a method and a device for detecting a response message. The detection method comprises the following steps of: performing demodulation and descrambling on the estimation of a symbol sequence on E-HICH, and removing idle bits to obtain a soft-decision bit sequence without the idle bits; calculating a relevance value c between the soft-decision bit sequenceand a signature sequence corresponding to the response message; and determining a detection threshold value based on the prior probability PNACK of a non-acknowledgement NACK message, the prior probability PNACK of an acknowledgement ACK message and the relevance value c, and judging whether the received response message is the NACK message or the ACK message according the detection threshold value. The device comprises a relevance value c acquisition module, a detection threshold value determining module and a response message type determining module. By applying the method and the device, the detection performance of the response message on the E-HICH can be improved.