An operational modal parameter identification method based on strain response under colored noise excitation is proposed in this paper. Firstly， starting from the frequency response function of strain， the method of operational modal parameter identification is applied to the strain response signal under colored excitation， and the modal parameter expression of multi degrees of freedom system is deduced using only strain response. Secondly， the numerical simulation of cantilever beam is carried out， the error of the modal identification is analyzed， and the effectiveness of this method is verified. Finally， through the cantilever experiment， it is verified that this method still has high recognition accuracy in the real colored noise environment.