Base of cantilever sheet type rail post and installation method of base

The invention relates to a base of a cantilever sheet type rail post and an installation method of the base. The base comprises a backboard and multiple fixing bases, wherein the fixing bases are arranged on the backboard; the backboard is provided with bolt holes; each fixing base comprises oppositely-penetrating bolts, two clamping boards and a clamping piece, the clamping boards are opposite and are arranged in a spaced mode and are provided with screw holes, the clamping piece is arranged in the gap between the clamping boards and provided with positioning holes and fixing holes, and the oppositely-penetrating bolts are arranged in the positioning holes and the screw holes. The base of the cantilever sheet type rail post enables the rail post to have good perpendicularity and stability in the installation process of the rail post, and the vertical interval and straightness of installation of the base can be well controlled. Meanwhile, the clamping pieces of the base are detachable, lateral stone materials are convenient to install, and the post is fixed with the multiple clamping pieces, so that the firmness is higher.