A method for preparing organic-inorganic hybrid nanoflower by electrodeposition is provided, which relates to the technical field of enzyme immobilization. An aqueous solution of a rare earth nitrate is mixed with a biological enzyme and a nitrate to obtain a mixed solution; the rare earth ions in the rare earth nitrate are one or more selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb and Y ions; the biological enzyme is α-amylase, horseradish peroxidase or laccase; then, the mixed solution is electrodeposited with a three-electrode system consisting of a working electrode, a counter electrode and a reference electrode to obtain an electrodeposited film on the surface of the working electrode; thereafter, the electrodeposited film is washed and dried successively to obtain organic-inorganic hybrid nanoflower.