Provided are a phase transition material fluid and a proppant formed therefrom, wherein the components for preparing the phase transition material fluid comprise in percentages by mass: a supramolecular building block 10 to 60 wt %, a supramolecular functional unit 20 to 50 wt %, a dispersant 0.1 to 2 wt %, an inorganic co-builder 0.1 to 1 wt %, an initiator 0.1 to 1 wt %, the balance being a solvent. The supramolecular building block comprises a melamine-based substance and/or a triazine-based substance; the supramolecular functional unit comprises a dicyclopentadiene resin; and the dispersant includes a hydroxyl-bearing polysaccharide substance and a surfactant. After the phase transition material fluid enters the reservoir, it may form a solid substance to prop the fracture under the action of supramolecular chemistry and physics.