A pre-loadable biological heart valve capable of rapid rehydration and a preparation method thereof. The preparation method comprises a cross-linking treatment, wherein a biological valve is cross-linked by soaking in an aqueous glutaraldehyde solution; a hydrophilic treatment, wherein the biological valve is soaked in a solution containing a hydrophilic molecule and a condensing agent, to allow the hydrophilic molecule to be immobilized on the biological valve by chemical grafting; and a drying treatment, wherein the biological valve after the hydrophilic treatment and the cross-linking treatment is dried to obtain a pre-loadable biological heart valve capable of rapid rehydration. The pre-loadable biological heart valve prepared by the preparation method of the present disclosure achieves rapid rehydration, and the crease can be quickly flattened after rehydration, bringing convenience during use.