The overlying water is the interface between water and the atmosphere, and its water quality is an important indicator for evaluating the environmental quality of park landscape water. This study collected landscape overlying water samples from eight parks in Harbin urban and applied the three-dimensional fluorescence spectroscopy parallel factor analysis method to detect the fluorescence spectral characteristics of dissolved organic matter (DOM). DOMs source and composition characteristics and the correlation between fluorescence spectral index, component fluorescence intensity, and physicochemical index were analyzed. This provides a reference basis for the environmental quality evaluation and pollution prevention of urban park landscape water. The study results showed that DOMs fluorescence index (FI) ranged from 1.71 to 1.98, with an average value of 1.185, suggesting that the source of DOM has both exogenous and endogenous characteristics. The biological index (BI) ranged from 0.97 to 1.34, averaging 1.09; the freshness index (β/α) ranged from 0.91 to 1.19, averaging 1.101, indicating strong characteristics of the recently endogenous composed of DOM. The humification index (HI) ranged from 0.186 to 4.126, averaging at 2.143, indicating a low degree of humification. Five kinds of DOM fluorescent components were identified in the water samples: fulvic-like acid substance (Ultraviolet fulvic-like acid component C1, visible fulvic-like acid component C2), protein-like substance (tryptophan-like component C3, tyrosine-like component C5), and humic-like acid component (C4). The relative concentration of humic-like substances (C1, C2, and C4) was higher than that of protein-like substances. There was a significant (p<0.01) positive correlation among the three kinds of humic-like substances, and all were significantly (p<0.01) negatively correlated with C5. However, the correlation between C3 and other fluorescent components was insignificant (p>0.05). Various physicochemical indices impact on FI was insignificant (p>0.05). The value of pH and BI, β/α (p<0.01) exhibited a significant positive correlation and a significant negative correlation with HI (p<0.05), respectively. The negative correlation between DO and C3 and the positive correlation between DO and C5 were significant (p<0.05). Humus-like substances were significantly positively correlated with TOC, TP (p<0.01), and COD (p<0.05), while fulvic-like acid substances were also significantly positively correlated with TN (p<0.05). Conversely, C5 negatively correlated with TOC and TP (p<0.01). Based on the principal component analysis results of the overlying water physicochemical indices DOM fluorescence spectral index and component fluorescence intensity, it can be concluded that compared to the fluorescence spectral index, the fluorescence intensity of humic-like substances and C5 can better distinguish different water samples and be used to evaluate the environmental quality of landscape water.