Environmental effectiveness refers to the influence and harm on products and materials resulting from the effects of various environmental factors. In their actual usage in a complex environment, products are put forward to address a series of urgent engineering problems caused by environmental effectiveness. However, environmental effectiveness is not extensively studied, and it is not sufficiently considered in the process of product reliability design and analysis. To solve these issues, we apply an ontology and rule reasoning method to design an ontology-based environmental effectiveness knowledge application system. The system comprises four layers: ontology, reasoning, data storage, and knowledge application. With the use of this system, specific measures for possible product failures caused by the environment can be deduced on the basis of the existing environment and failure data. This system can satisfy the requirements for extracting useful environmental effectiveness knowledge from large data to assist reliability designers in realizing complete reliability designs. A semi-intelligent analysis for environmental effectiveness can be applied to reliability analysis and design works. Finally, a case study of a rubber seal for environment protection design is presented to illustrate the applications of the system.