Abstract: Operating in the heavy congested SW band, HF radars use a quasi-random step frequency signal to avoid the interference bands. However, the sidelobe of this signal after matching processing is very high, thus would greatly debase the radars performance. In this paper, a range sidelobe processing technique is proposed on a basis of delicate signal analysis and a NN based algorithm is applied to realize the optimization computing. Simulation re-sults demonstrate this method could successfully suppress the maximum sidelobe with good numerical stability.