Abstract: As the flying time and speed of missile increase, traditional methods such as using the structure′s own heat capacity to absorb the dissipated heat and control the temperature increase of core electronic components had met dilemma. This paper carries out parameterized modeling and analysis for missile platform phase change heatsink using composite paraffin expanded graphite PCM(phase change material). Several relevant parameters affecting the heatsink efficiency of a practical project and their optimized values are calculated by using the parameterized analysis flow of DM(Design Modeler) of Ansys Workbench and using Icepak and the method of virtual specific heat capacity.