The technical field of enzyme immobilization, and particularly, an organic-inorganic hybrid nanoflower and a preparation method thereof. The organic-inorganic hybrid nanoflower is a flower-like immobilized enzyme formed by self-assembly of a layered rare earth compound as an inorganic carrier and a biological enzyme as an organic component. The layered rare earth compound is Ln2(OH)5NO3·nH2O, where Ln is one or more of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Y, and n=1.1-2.5. The biological enzyme is one or more of α-amylase, horseradish peroxidase, or laccase. A layered rare earth compound is used as the inorganic carrier for the organic biological enzyme to form the flower-like immobilized enzyme. The immobilized enzyme has better stability and higher catalytic performance when compared with a free enzyme.