Abstract: The effective demonstration and exploration of the historical data from power plant’s control process can help users to understand the operating condition of power units quickly and deeply.Since historical data has the characteristics of long time span,multi-scale and high density,and contains complex,high-dimensional and multivariate parameter sets simultaneously,it has brought great challenges to visual design.In this paper,the integrated visual mapping for time-series data space and high-dimensional parameter space is studied from the perspective of power unit operating conditions and parameter correlation.First,a multi-facet overview is de-signed to navigate the global operating state of the power unit,followed by a multi-resolution operating condition view,which can effectively support the display and exploration of multi-level operating conditions.Then,to realize the flexible selection and filtration of parameters of the power unit,a parameter navigation view is designed to support the hierarchical exploration of multivariate parameters.It can be also well-coordinated with the operating condition view to support users to explore the parameter characteristics of different time periods and different system levels.Based on the above methods,a visualization tool,called iDCS,is designed and applied to the visualization and analysis of the real power unit control data,and the validity and applicability of the system are verified.