"生命周期研究法" can be translated into English as "Life Cycle Assessment (LCA) Method" or more literally as "Life Cycle Research Approach".
Life Cycle Assessment (LCA) Method is a commonly used term in environmental science and engineering, referring to the systematic analysis of the environmental impacts of a product, process, or service throughout its entire life cycle.
Life Cycle Research Approach is a more straightforward translation that emphasizes the research methodology focused on the life cycle.
In most academic and professional contexts, Life Cycle Assessment (LCA) Method would be the preferred choice.