The frequency range of traditional chaotic detection methods is very narrow, complex multioscillators are essential when we meet the demand of wideband signal. According to this problem, one new algorithm is proposed in this paper, which made full use of periodic signal frequency characteristic and frequency detection approach based on Duffing oscillator. This method made spectrum analysis of oscillator output, abandoning the traditional periodic driving force, that could reduce the difficulty of tuning and increase the system stability. Simulation results show that, this method can achieve accurate detection of frequency signal, compared to others, new method has high accuracy (10-4magnitude) and low complexity in implementation.