Disclosed are a method and a device for detecting displacement in elastography. The method comprises: acquiring a target point, acquiring a cross-correlation phase calculation location of the target point in a second frame image calculating a cross-correlation phase according to the cross-correlation phase calculation location calculating a longitudinal displacement result according to the cross-correlation phase and calculating a gradient of the displacement result to obtain a strain result. Through the elastography method and device, I/Q-channel echo baseband signals, obtained by downsampling, of two frames before and after compression are acquired, displace information between the two frames is rapidly detected by guiding phase estimation, and axial gradient calculation is performed to obtain strain information, which can not only obtain a strain image of high quality but also reduce the calculation amount, thereby satisfying the clinical real-time requirement.
