Abstract: It has a great significance to analyze spatial and temporal distribution of pollutants and realize the accurate judgment of the pollution sources for improving the water environmental quality and function. The coastal areas of Daya Bay as research object, and the surface and bottom water quality of Daya Bay was evaluated by using excessive multiples weight method and spatially integrated technology. Positive matrix factorization model was used to quantify the contribution of different pollution sources and quantitatively analyze the contribution rate of pollution sources. The detailed information on results was following: In the surface water, the Daya Bay sea area was mainly slightly polluted, and there was mild pollution in the southeast, and moderate pollution in the northwest Aotou area. In the bottom water, the sea area was mainly slightly polluted, and the northwest Aotou area was heavily polluted. The surface water was mainly affected by domestic sewage (15%), river (15.5%) and suspended particulate matter (44.3%); the bottom water was affected by suspended particulate matter (40.6%) and petrochemical wastewater (37%). In summary, the analytical framework and integrated methodology based on spatial integrated technologies and Positive matrix factorization model enabled to accurate comprehensive evaluation of bay water quality and analysis of bay pollution sources. It also provided theoretical basis and data support for water environmental management of Daya Bay.