Abstract: In order to effectively capture BeiDou Satellite Navigation (BDS) weak signal information under the influence of external RF signals and mixed frequency processing noise of navigation receiver, the automatic acquisition method of BDS weak signal based on density clustering is studied. The density clustering is used to design the satellite beam direction from the cluster center of BDS signal source in combination with the cluster center, and constrain the receiving range of satellite navigation signals, and resist the airspace interference of jamming signals. The noise information of navigation signal under the effect of beam anti-jamming is removed by wavelet threshold method. The correlation between the de-noised navigation signal and the known weak signal is calculated using the correlation function modulus calculation method. If the correlation is greater than the threshold value, the de-noised navigation signal is a weak signal. The experiment verifies that under the interference of external RF signals and mixers, this method has the ability to automatically capture the weak signals of BDS.