A scheme of dynamic range optimization for Microwave Photonic Link with Distributed Feedback laser(DFB) was proposed. The nonlinearity of the laser was experimentally studied. The relationship between the bias current and the linear performance of the DFB laser was analyzed experimentally. Based on the experimental results, the linear system of Mach-Zehnder modulator(MZM) system was established. The experimental results show that the third order intermodulation of the system is suppressed, when the center frequency of the input frequency signal is 4 GHz and two tone separation is 10 kHz, the three order distortion is suppressed 23.1 dB and the spurious-free dynamic range can be improved by 8.68 dB.