This article focuses on the difficulty of evaluating the effectiveness of rural small and micro black and odorous water treatment projects. Taking the Majia River and Baitu River treatment projects in Z town as the research object, an environmental engineering effect evaluation model based on multi parameter dynamic monitoring is constructed. Based on continuous monitoring of three core indicators of transparency, dissolved oxygen, and ammonia nitrogen for three months, combined with the water quality index method (WQI) and fuzzy comprehensive evaluation method, a quantitative evaluation model for comprehensive water quality index (CWQI) is established. By standardizing the monitoring data and using the entropy weight method to determine indicator weights (dissolved oxygen 0.4, transparency 0.3, ammonia nitrogen 0.3), the changes in CWQI values before and after remediation were compared. Combined with engineering measures such as river dredging and water diversion, the evaluation ability of the model for the treatment effect of rural small and micro black and odorous water was verified. In the field of ecological environment engineering monitoring, the application of dynamic monitoring model evaluation methods is helpful for engineering remediation effect, engineering data validation, sensitivity analysis and evaluation, trend feature analysis, and provides a reference technical approach for the long-term management of small and micro black and odorous water in rural areas.