The impervious surface increase driven by rapid urbanization directly causes flood peak and total runoff increasing in watershed. An important way to reconstruct eco-hydrological process of watershed is sponge city construction. Sponge city can enhance the pervious surface through ecological infrastructure network construction. However, the role of sponge city construction in eco-hydrological process of spongy body in watershed is still unclear. This paper takes Honghu Area of Buji River watershed in Shenzhen as an example to assess eco-hydrological process after sponge city construction. The assessment method was online continuous monitoring of hydrological process elements in rainy season. The results showed that rainfall volume in rainy season affected indirectly the total surface runoff in Honghu Area on mesoscale. The rainfall intensity significantly affected the peak runoff flow in Honghu Area (P<0.05). The daily rainfall volume had a very significant effect on the water quality of Buji River (P<0.01). Pervious surface in Honghu Area increased through sponge city construction of 28.0% (0.85 km²). The construction of biological retention facilities and permeable pavement and others strengthened the evapotranspiration and infiltration process in Honghu Area. Sponge facilities promoted Honghu Area reduced the total surface runoff in rainy season by 97.2% (2.4872 million m³). Peak flow was reduced by more than 98.2% under two typical rainfall. The water level of waterlogging points was reduced to less than 7.8 cm in rainy season. The rest 2.8% surface runoff formed river runoff of Buji River. The reduction of surface runoff had no directly quantitative relationship with sponge area (proportion). The pollutants intercepted time and space improved with the water retention capacity in Honghu Area. Adequate interception of pollutants promoted monthly average concentration of SS (suspended solids) discharge lower than 15.60 mg/L. The lower SS concentration indicated that the total amount of pollutants from runoff decreased and migrated slowly to Buji River. Effective interception of pollutants promoted black and odour in Buji River dissolved and water quality improved to Class IV. The influence of sponge city construction on eco-hydrological process on mesoscale was different with that on microscale. The quantitative relationship between rainfall and eco-hydrological process of typical projects was not obvious. School, road and community park used green roof and permeable paving and others to strengthen infiltration and evapotranspiration. The sponge facilities promoted the typical projects reduced runoff in rainy season by more than 99.0%, and reduced peak flow by more than 97.0%, and controlled monthly average concentration of SS below 17.10 mg/L. In conclusion, our research results strongly suggest that sponge city construction can reduce the total runoff, peak flow, ponding water level and runoff pollution in Honghu Area. Coupling construction of source emission reduction facilities and storage facilities on microscale and mesoscale is an effective way to improve the eco-hydrological processes of similar watershed.