Abstract: Compared with ordinary chaos systems, hyperchaos systems have excellent security in communication because hyperchaos sequence has better complexity and randomicity. The thought of applying dimension-lowered hyperchaos sequence to spreading-frequency communication is proposed. A dimension-lowered model is designed to generate hyperchaos sequence with well-proportioned stochastic diffusion, then the capability of hyperchaos sequence is analyzed in defail. The sound spreading-frequency modulation model based on hyperchaos random sequence is tested by practical circuit experiments. Measuring results verify the validity of designing thought. Another idea is briefly introduced for the deep research into spreading-frequency secrecy communication technique.