In this paper, continuous acoustic monitoring was conducted from July 5-9, 2024 at 10 sample points using City Park A in City B as the experimental sample site. Combined with the bioacoustic dominance degree, power spectral density, acoustic index and BFAST temporal analysis model, we systematically explored the changing trend of the city park acoustic landscape. The results show that: (1) the sound level spatial and temporal differentiation is significant, the cultural promenade, the south gate and the north gate are the noisy core area, and the highest proportion of the whole day exceeds 70 dB, while the sculpture garden and the ancient pavilion sound level is mostly lower than 65 dB. (2) in the subjective perception of the acoustic landscape, the artificial sound, the natural sound and the living sound accounted for 23.1%, 54.3%, and 22.6% respectively, and in the morning, due to the biological activities and the tourists’ entry to the park, the cumulative value of the subjective perception reached the highest value of 1357.298.(3) The daily change of acoustic index is characterized by distinctive features, the BIO index dropped to the bottom in the early morning due to traffic disturbance, while the NDSI index reached the peak in the early morning. The AEI index was higher from 08:00-18:00, and the ACI index fluctuated between 9000-18000 during the day.(4) The BFAST model can decompose the temporal trend of the acoustic landscape efficiently, and it can identify more accurately the trend mutations.