The invention discloses a metal rapid solidification test substrate which comprises a cooling sheet and a cooling chamber; the cooling sheet is fixedly laid on the top of the cooling chamber through acompaction device; the cooling chamber is internally provided with a cooling channel; cooling media which flow in the cooling sheet and the cooling chamber respectively are in heat conduction contact. The metal rapid solidification test substrate has the beneficial effects of having the characteristics of simpleness and convenience in operation through detachable assembly of the cooling sheet andthe cooling chamber; and capabilities of being used to replace an original substrate and meeting various demands without frequently changing the whole substrate when realizing rapid solidification, and thus greatly saving the experiment cost. Particularly for studying influences of different metal materials, plating materials, surface textures and the like on rapid solidification, as the novel substrate which only needs to change the cooling sheet without being changed, the metal rapid solidification test substrate is huge in effect.