A new airborne laser bathymetry system is developed. Compared with the previous one, the new system is improved in data-acquisition rate, accuracy of measuring point position, ability of shallower water detecting and automatic operating. 1000 Hz laser is used to improve density of points gird, backward signals are separated into two channels of deep water and shallow water to enhance the ability of detecting signal from shallow water, high accuracy inertial measurement unit (IMU) and global positioning system (GPS) are equipped to improve the measuring point accuracy of orientation and depth. In addition, tide correcting and wave correcting are applied to improve the depth accuracy in data processing. The new system has been tested several times over a sea.The obtained results show that the new system can be practical in ocean survey with good depth accuracy and efficiency.