This three-part paper introduces the design of dynamic simulation platform for power market & power system（DSPMPS）， which is a novel simulation platform for the dynamic interactive simulation study of power market and power system. As part one， requirements of power market simulation and technical supports for simulation platform are reviewed; the design objective is presented. The function design of DSPMPS is introduced through the three essential elements of simulation platform， namely information acquisition， knowledge extraction and decision support. The function design will be the design basis for both support layer and application layer. Important tasks are the implementation of experimental economics， multi-discipline dynamic interactive simulation， on-line quantitative risk analysis， multi-criterion and multi-control decision supports. Research work already carried out has validated the effectiveness of DSPMPS.