A hyper dimensional multiplexed chaos communication system was proposed based on nonlinear delayed feedbacks of electrooptical modulator.Different from traditional chaos communication system，the chaotic waveform is not produced by the semiconductor but by the electro-optical modulator.The scheme is advantageous of high nonlinear dimension，easily reproduced and manipulated accurately.The encryption method of signals modulating feedback delays and cross-correlation decryption method were illustrated.High rates of multiplexing and demultiplexing were numerically simulated for three channels.The main factor for error bit rate was analyzed.The influence of optical fiber on the multiplexed chaos communication system was further investigated.The research results indicate that the influence of optical fiber on chaos synchronization can be reduced significantly and the original signals can be recovered successfully as long as corresponding gain compensation schemes are adopted.