With the limitation of single-pulsed laser ranging technology in long distance laser ranging, a new ranging technology based on the cross-correlation between the transmitted pulse train is proposed. A laser system which can modulate pulse’s intensity and intervals is applied to simulate different echo pulses. A series of experiments are designed to explore the abilities of the technology in improving signal to noise ratio (SNR), suppressing noise and measuring time, and good results are got. The SNR is improved from 0.11 to 5.92, which extends laser ranging, decreases alarm rate of the detection system and increases ability of exploring weak echo pulse.