To overcome some limitations of the modal identification method based on the second-order blind identification (SOBI) algorithm, a new modal parameter identification method based on the Hankel matrix joint approximate diagonalization (HJAD) technique was proposed. In this method, the Hankel matrix, which is commonly used by the stochastic subspace identification method, was diagonalized using the joint approximate diagonalization technique in order to separate modal responses and identify modal parameters. Compared with the SOBI-based modal parameter identification method, the proposed method was easy to implement when only additional time-lagged response data was needed. The numerical and experimental analysis results show that the proposed modal parameter identification method overcame the limitation of not being able to estimate more active modes than the number of available sensors.