The invention relates to a method and a device for protecting the safety of an elevator well in the house building process. The device comprises a steel bar mesh sheet matched with the size of he elevator well and a protecting cover plate covered on the mesh sheet; the steel bar mesh sheet is welded by a plurality of vertical and transverse steel bars which are alternate in certain distance; a plurality of the vertical and transverse steel bars are extended for certain size on the outer edge of the formed rectangular mesh sheet; and four corners of the protecting cover plate are bond and connected with the steel bar mesh sheet. The method comprises the specific steps for implementing the device. Compared with the prior art, in the method the steel bar mesh sheet is used as a relatively permanent device and is anchored into beams on the periphery of a main structural floorslab or steel bars of the floorslab; the method of covering a protective plate on the mesh sheet replaces the prior art and avoids the possibly falling off from the elevator well. The method and the device can save mass leasing expense of steel tubes and fasteners, the purchasing and mounting expense of bamboo and an elevator protecting door, has simple construction, saves mass labor expenses and has good economic and social benefits.