Abstract: To understand the impact of ships and fishing ban policies on low-frequency ambient noise spectral levels in offshore waters, the one-third octave power spectrum density (PSD) in the frequency band of 25~500 Hz of the ocean ambient noise data measured in the waters near shipping lane and far off shipping lane in Qingdao offshore are analyzed. The analysis results show that in the frequency band of 30~100 Hz, the ocean ambient noise spectral level near the shipping lane is about 5~10 dB higher than that in other sea areas. The spectral level of ocean ambient noise in fishing seasons is about 4~5.5 dB higher than that in the banned fishing periods in 150~400 Hz. The features of low frequency environment noise spectral levels presented in this paper have important reference values for the analysis and application of the low-frequency characteristics of offshore ambient noise at home and abroad.