Abstract: Based on the public data of the Laizhou Bay marine environment since 2015, this paper analyzes the distribution characteristics and changes of water quality and eutrophication in Laizhou Bay, and puts forward some suggestions for the environmental pollution in the Bay. The results show that the water environment and eutrophication of Laizhou Bay waters have changed significantly. The content of dissolved inorganic nitrogen (DIN) as well as the eutrophication area has a significant reduction. The comprehensive management of the Bohai attack is significantly effective. However, the pollution near the Xiaoqing river and the Yellow River estuary is still serious, and the water environment in the bay is degraded compared with that in 2001, which is mainly manifested by the decrease of pH, the slight decrease of dissolved oxygen (DO) and the aggravation of the imbalance of N/P ratio. The bay ecosystem is in a sub-health state, main limiting factor is the fluctuation of biological density, and the invasion of Spartina alterniflora also has a negative impact on the ecological environment health. It is recommended to strengthen the "source control, process supervision, and end treatment" of pollutants in accordance with the governance concept of "Land and sea planning, river and sea consideration, coordinated governance", establish the total pollutant control system in Laizhou Bay, scientifically calculate the allowable emissions of key pollutants such as total nitrogen and ammonia nitrogen, and adopt a combination of "emission reduction" and "capacity increase" to realize effective prevention and control of key pollutants and promote continuous improvement of ecological environment quality in the Laizhou Bay area.