The invention provides a supporting structure for multi-layer heat sinks with a large dimension and a large span, which effectively solves the problem that the heat sink supporting structure has largeflexibility deformation when the spacing between the inner-most heat sink layer of the multi-layer heat sink structure and the internal wall of a vacuum container is large. The supporting structure adopts the form of adjustable supporting rod and multi-fulcrum, replaces the supporting rods (16) with different heights to realize the height adjustment of the heat sink supporting structure, and meets the different bearing requirements of the heat sink supporting structure by increasing or reducing the number of the fulcrums. A heat sink framework upper supporting wheel (10) arranged on a heat sink framework can freely slide along the axial and radial directions on the guideway (12) of the heat sink supporting structure, thus eliminating the heat sink due to temperature gradients and the expansion amount effects of the heat sink framework in the axial and radial directions.