Abstract: In order to get the high-quality observation data of the bottom current for the development and design of marine oil and gas, this paper provides a design of bottom current observation system which is suitable for the deep sea. This system has been applied in the Lingshui and Songtao sea area in the northern South China Sea for 100 days and 5 days, respectively; and these applications provide precious basis data for the subsequent development of oil and gas. During the two observation periods, the maximal bottom currents are 25.84cm/s and 16.70cm/s, respectively; and the inclinations of the bottom current meter are 3.39° and 1.72°, respectively, which are much less than the design value and insure the high quality of bottom current.