The invention discloses a solid wood door manufacturing method capable of preventing deformation. The method is characterized in that the log is cut into a single board when the log is treated, edgesand angles are removed according to the single board maximum principle, so that the log can be maximally utilized, a large plate are spliced through rectangular plates, the small wood is changed intoa large plate suitable for door manufacturing, then a double-layer large-scale plate is formed through the gluing and pressing treatment of the two layers of rectangular plates, the double-layer plateis adopted to be cut into a door core base plate, a steel frame fills the base plate, the shape of the door core is kept by using the steel frame, the plate deformation force is prevented through thestress of the steel plate the during the expansion and contraction of the wood, and the door core is prevented from being deformed.