A coupling nonlinear dynamic system based on semiconductor lasers with phase conjugation and cross-phase conjugation feedback is presented. The principles of frequency detuning and frequency enhancement are analyzed, and four phase conjugation feedback schemes for frequency enhancement of two chaotic lasers are studied. It is found that the chaotic spread frequency effect of the laser can be increased to 4 times when the phase conjugation feedback is applied to a single laser. When the chaotic frequencies of two coupled lasers are increased with phase conjugation double-feedback, it is found that the frequencies of chaotic oscillation are obviously increased to more than 5 times and spectra are obviously broadened. When the cross-phase conjugation feedback is operated on a laser, the chaotic oscillation frequency can be increased to 4.4 times. When the cross-phase conjugation feedback is operated on two lasers, the chaotic oscillation frequencies of the two lasers are increased significantly, which can be increased to 4 times or 6 times, and the spectra are greatly broadened. In addition, a method for increasing the chaotic oscillation frequency is proposed based on phase conjugation double-cross reverse feedback. Results show that the chaotic oscillation frequencies of the two lasers can increase to 4.2 times or 5.9 times with the increasing feedback level, and the spectra are effectively widened.