This paper presents an optimum weighted cumulation target detection (OWCTD) algorithm and prewhitening processing matrix for resonance region multi-carrier radar, and points out that the target detection performance of the wideband multi-carrier pulse radar using OWCTD algorithm is better than the traditional match filter algorithm. In addition, this paper deduces that the target velocity has little effect on the detection performance of the OWCTD algorithm. Finally, the asymptotic target detection probability as SNR tends to infinity is given, and the OWCTD algorithm performs better than the traditional match filter target detection algorithm at all target velocity.