The invention discloses a method for preparing methyl acraldehyde from tert-butyl alcohol, and in particular, relates to the method for preparing methyl acraldehyde from tert-butyl alcohol as a starting raw material. The method includes that the raw material passes through a fixed bed reactor filled with catalysts, the fixed bed reactor is divided into n reaction sections from a raw material inlet to a raw material outlet, and all the reaction sections are filled with the catalysts with different catalytic activities; the catalytic activity of the catalyst of the first reaction section is greater than that of the catalyst of the second reaction section, and the catalytic activities of the catalysts are increased successively from the second reaction section to the last reaction section; n is an integer of 3-10.