The present disclosure provides an integration method for multiple centralized units, an integration device for multiple centralized units, and an integration system for multiple centralized units. The integration system for multiple centralized units includes a centralized unit center, the centralized unit center is configured to integrate multiple logical centralized units, the multiple logical centralized units share one or more function modules at corresponding levels according to a preset service requirement, and the function modules at the corresponding levels are configured to provide function services at the corresponding levels for the logical centralized units.