Marx believes that there are two closely related ways in human thinking and understanding, namely, the complete representation evaporated into abstract provisions and the concrete reproduction resulting from abstract provisions in the formation of thinking. The main body of river engineering starts from the reality and sensibility, around the core element of “scene”, germinates the original idea in the thought field according to the needs of the engineering function, and forms the target scene of the interactive design stage of the engineering product. It evaluates, optimizes and verifies the river engineering in the idea, improves the rationality of the engineering design, and constructs the river engineering in the material space. Then it leads to the rational abstraction, until the concrete reappearance of rationality, determines the overall engineering design scheme, and conceives the engineering practical application scene at the conceptual and abstract level. From the field of thought, material space and scene application, the dialectical thinking of Marxism can be expanded in the construction of river engineering scene. The occurrence and application of river engineering scene, its regional and situational characteristics determine the irreducibility of the project. The overlapping and coupling of many scenes blurs the boundaries of the subject and object of the project, and extends the new behavior to adapt to the new social scene. It drives people to practice intelligently with “practical wisdom” that is “beyond the ability to apply general rules”, forms a general code of conduct for “internal governance of engineering community”, and effectively integrates a practical ethical code into the whole process of river engineering conception, design, construction and operation.