A laser echo digitizing system based on a new switched capacitor array technology was designed. By using the system, the sampling rate of 5 Gigabit samples per second was achieved. Multichannel sampling was realized by using a single chip analog digital converter. The system had a great potential for development. A laser echo digitizing circuit based on DRS4 chips was designed, a laser testing system was built and the signal sampling experiment based on DRS4 chips was carried out. The results showed that the laser echo digitizing circuit could obtain a sampling rate of 5 Gigabit samples per second, could realize multichannel sampling, could increase the field of view and could reduce the power consumption and cost of the system.