The invention discloses a well group well spacing method of a microbial oil displacement oil recovery technology. A set of combined injection-production well pattern of horizontal well exploitation and vertical well injection is deployed in a thicker sandstone oil reservoir by utilizing a microbial tertiary oil recovery technology, and the combined injection-production well pattern needs to meet the requirements of plane correspondence, longitudinal three-dimension and bottom injection and top production; the vertical well injection refers to injecting microorganisms into a bottom area of a sandstone reservoir by using a vertical well, and the horizontal well exploitation refers to deploying the horizontal section of a production well in a top area of a thicker sandstone reservoir; the plane correspondence refers to overlapping the horizontal section of the injection vertical well and the horizontal section of the production well after being projected to the plane in an overlooking state, and an up-and-down corresponding relation is achieved; and the longitudinal three-dimensional refers to that the injection section of the vertical well and the horizontal section of the productionwell are arranged in parallel at different depths in the sandstone reservoir, and a three-dimensional well pattern is formed in the section parallel to the gravity direction and perpendicular to a main shaft of the horizontal section of the production well. The well group well spacing method has the advantages of being higher in oil sweeping efficiency, high in oil extraction capacity, higher infinal recovery ratio and the like.