In order to break through the condition limit，the guide rod commonly been used to detect the weak acoustic emission signal, but the signal might been weaken. In this paper, firstly the design method based on the resonance theory for the resonant conductor lever were developed, and the manufactured resonant conductor lever were studied in the experiments, the effect of the signal amplitude amplification and band-pass filter have been recommended, which were related to the factors such as different materials, different resonant lengths, different cross-sectional area ratio, different length of the large end and little end etc.