Life cycle assessment (LCA) has proven to be a useful tool in assessing environmental technologies in a retrospective manner. To fully uncover the environmental improvement potential while advancing technologies under technical and environmental constraints, this study recommended approaching the LCA proactively to assess the progress of parameter optimization before determining critical parameters. To that end, the present work introduced a multimethod eight-step (MMES) analysis scheme, which included an integration of LCA with Plackett-Burman multifactorial design, central composite design, and multi-objective optimization. By creating a large number of scenarios through experimental design, we jointly optimized technical efficiency and environmental sustainability, which allowed for the identification of critical parameters that likely had contradictory influences on different objectives. Through a case study concerning the bioaugmentation of constructed wetland (CW), we applied the MMES scheme to optimize the culture conditions of the strain Arthrobacter sp. ZXY-2 for enhanced atrazine removal. The results showed that, by reducing the Na₂HPO₄·12H₂O concentration from 6.5 g/L to 6 g/L in the culture condition, we decreased the freshwater ecotoxicity potential and maintained a high level of atrazine removal. Regarding the production process of microbial inocula, the strain ZXY-2 grown at the optimized culture reduced the total environmental impact from 13% to 50% compared with the original culture and helped the CW exhibit more favorable atrazine-removal performance. Taken together, the case study demonstrated the effectiveness of using the MMES scheme for parameter optimization of environmental technologies. For future development, the MMES scheme should extend the application to more fields and refine uncertainty management.