Variable diameter pile and column integral structure and preparation method thereof

The invention relates to a variable diameter pile and column integral structure and a preparation method thereof, and belongs to the technical field of building construction. The problems that as forexisting variable diameter piles and columns, precast piles and pier columns are connected through a connection mode of variable cross-section connection, the bending moment at the joint is large, thedamage is prone to being caused, the technology is complicated, and the construction efficiency is low are solved. The variable diameter pile and column integral structure includes a precast sectionwith the integral structure and a second pile section, the precast section includes a column section, a pile and column connection section and a first pile section which are sequentially connected, the first pile section and the second pile section are fixedly connected through the pile connection section, the position of the pile connection section is the position of an inflection point, and theposition of the inflection p