To deal with interactions of geological objects with rock engineering projects under quick construction in China, which both together comprising one complex huge system, the Meta Synthesis is set up for various sources of knowledge to be combined to accomplish joints of experience, inference with monitoring for decision making in engineering geology. From this theoretical basement, this paper presents observations, judgment and tests are used to fulfill interaction matrix for analysis of multiple factors with interactions. Therefore the engineering geological interaction approach (EGI) is put forward as one applicable method for interaction analysis. From viewpoint of Meta Synthesis and actual situations of natural evolution and engineering disturbance of geological objects, the opinion of Dynamic Controlling (DDC) is formed. This opinion takes account of primary and secondary variations of objects, meets requirements of plan and selection schemes, and adopts some indices as engineering geological zonation (EZI), comprehensive suitability index (CSI), and assessment of the degree of reinforcement demand (DRD), etc, for assisting in decision making with aspects to agreement of engineering with the environment.