In view of the problem of slow-moving target detection in heavy clutter background, a slow-moving target detection method is proposed based on the dual polarization fire control radar. The design of intra pulse time-varying polarization Transmitter/Receiver (T/R) is used, and polarization orthogonality is utilized to suppress the impact of near-filed clutter on reception dynamics. Meanwhile, a closed form solution based on intra pulse time-varying initial phase pull-off target doppler is provided, as well as Field Programmable Gate Array (FPGA) implementation. The proposed method can reliably achieve the detection of slow-moving targets in heavy clutter background, with high engineering feasibility. Finally, the effectiveness of the proposed method is verified through Matlab simulation.