A flare-type tension leg floating wind turbine foundation is provided, which includes a top support platform configured to support a tower frame, a blade and a wind turbine generator set; a bottom support structure connected to a plurality of tension legs; at least three hollow upright columns connected between the top support platform and the bottom support structure and arranged around a vertical center line of the floating wind turbine foundation, each of the at least three upright columns being inclined outward from a lower end to an upper end with respect to the vertical center line of the floating wind turbine foundation; and a ballast adjusting system provided in the upright columns and/or the bottom support structure.