The near-drilling tool can effectively overcome the shortcomings of the conventional measurement while drilling system, which is very suitable for use in complex formations or thin reservoirs, and has the advantages of convenient field assembly and low operating cost. Near-bit azimuth gamma measurement system is the core of its geological steering control. In this paper, two important modules of near-bit azimuth gamma ray measurement system are introduced in detail: sector measurement module and gamma counting processing module. Field experiments show that the system can quickly indicate the direction of the tool crossing the horizon, meet the requirements of field operation, and has a certain market value.