For the detection of weak and small targets of stealth ships, the traditional terminal guidance radar detection algorithm for anti-ship missiles is inadequate. This paper proposes new terminal guidance radar detection and tracking algorithm that can be used for detection of weak and small targets-track-before-detection (TBD) algorithm, which can solve some problems faced by traditional algorithms. This paper applies double-threshold TBD based on dynamic programming, and the engineering implementation flow chart is presented. The complexity analysis and test data verify the performance and potential value of the algorithm. Although the signal-to-noise performance needs to be improved, it still has a good practical significance for improving the detection of week and small targets by terminal guidance radar.