The invention discloses a capsule type pouring and filling method and structure for large-size karst pile foundation construction. The method includes the steps that A, the karst distribution range and rough dimension are determined through advanced exploration; B, the dimension of a capsular bag is determined according to the diameter of a pile foundation and the karst height, wherein the capsular bag is in a circular truncated cone shape; C, the capsular bag is sewn; D, a small amount of filler is injected into the capsular bag, the capsular bag is slowly placed downwards from the ground into the karst area with a rope along a pile hole; E, light bubble mixed materials are pumped into the capsular bag until the capsular bag is full; and F, the light bubble mixed materials are solidified fast, and construction of the pile foundation is carried out. Structurally, the karst area is distributed in a stratum, the pile foundation penetrates through the karst area and is embedded in the stratum, the pile foundation penetrates through the capsular bag via a cylinder hole in the capsular bag, the capsular bag and the karst area are connected, the capsular bag is filled with the light bubble mixed materials and is in the circular truncated cone shape, and the capsular bag is as high as the karst area. The capsule type pouring and filling method and structure for large-size karst pile foundation construction are reasonable in technology, economical, environmentally friendly, remarkable in effect, and capable of meeting the filling requirement of large-size karst pile foundation construction in karst regions.