Abstract: Wuyishan City is the key demonstration area of national ecological civilization construction, conducting evaluation of hydrological adjustment function service value is an ecological security assurance of national demand. However, the traditional experience formula methods were limited due to the complex hydrologic cycle in real condition. A distributed hydrological model, Distributed Time Variant Gain Model (DTVGM), is utilized to quantitatively estimate the hydrological adjusting ability and value under different vegetation cover conditions (forestland and bare fields) in Wuyishan City in 2010 and 2015. The kernel of this model is the elaborate simulation of hydrological cycle, which is fully considering the hydrological, meteorological, geographical distribution and other relevant information. The results indicate that:(1) The runoff regulation in 2010 and 2015 was 573 million m³ and 521 million m³, and the value was 3.593 billion yuan and 3.746 billion yuan, respectively. (2) Compared with the wet season in 2010 and 2015, the hydrological regulation adjustment decreased by 1.3 million m³ per day and 0.9 million m³ per day in the dry season respectively. (3) By applying hydrological adjusting calculation in the sub-administrative regions in Wuyishan City, Xingzhen Village and Yangzhuang Village had the highest hydrological value for more than a billion yuan that contradicts the value of less than 159 million yuan in Chongan Sub-district and Xinfeng Sub-district. The hydrological value of the other administrative areas was between 326 and 670 million yuan. With the good condition of vegetation, Wuyishan City had a strong capability of hydrological adjustment. However, it was also greatly affected by the regional climate conditions. The results indicated that the current vegetation coverage can keep high hydrological adjusting ability to respond to the normal weather conditions. However, in extreme weather conditions, e.g. extraordinary rainstorm, the current vegetation types and their corresponding hydrological adjusting ability will not be able to intercept the large amount of instantaneous rainfall.