Aiming at the mode division multiplexing system with high-mode group delay (H-MGD) using few-mode fiber, a cascaded independent component analysis (C-ICA) algorithm is proposed. The core idea of the algorithm is that two complex ICA algorithms are combined with a delay compensation module to eliminate the modal crosstalk induced by the mode multiplexer and the demultiplexer respectively. Then the proposed C-ICA algorithm is utilized to demultiplex the received signals from a 2×2 mode division multiplexing system, and the demultiplexing performance of C-ICA is compared with that of the common ICA in which the complex ICA algorithm is used only once. The simulation results indicate that the proposed C-ICA algorithm can implement mode demultiplexing of the mode division multiplexing system with H-MGD few-mode fiber validly. Moreover, C-ICA has better mode demultiplexing performance than the common ICA under the same conditions.