A modular building for civil use, comprising a wall panel, a floor panel and a vertical column, wherein the modular building further comprises a foundation block, and a protrusion is provided at a center of a bottom surface of the foundation block, and a recess is provided at a center of a top surface of the foundation block, and a protruding post matched with the recess of the foundation block is provided at a bottom part of the vertical column, and an engagement structure for connecting with the wall panel and/or the floor panel is provided on the vertical columns; wherein the vertical column is selected from a group consisting of a right-angle vertical column, a T-shaped vertical column and a cross-shaped vertical column; wherein the wall panel comprises an outer wall panel and an inner wall panel; and wherein the main body of the right-angle vertical column is a right-angle vertical plate, and the engagement structure of the right-angle vertical column is as follows: ends of two right-angle plates of the right-angle vertical plate are provided with a plurality of hanging lugs for connecting with the outer wall panel, and an arc-shaped overlap groove for overlapping with a floor panel is provided between two right-angle plates; the T-shaped vertical column comprises a T-shaped vertical plate, and a plurality of hanging lugs for connecting with the outer wall panel are provided at ends of the two transverse plates of the T-shaped vertical plate, and a plurality of hanging lugs for connecting with the inner wall panel are provided at an end of the vertical plate perpendicular to the transverse plate of the T-shaped vertical plate, and arc-shaped overlap grooves for overlapping with the floor panel are arranged between the T-shaped vertical plates; the cross-shaped vertical column comprises a cross-shaped vertical plate, and a plurality of hanging lugs for connecting with the inner wall panel are disposed at ends of four plates of the cross-shaped vertical plate, and arc-shaped overlap grooves for overlapping with the floor panel are disposed between adjacent cross-shaped vertical plates, wherein the four corners of the wall panel are provided with hanging posts matched with the hanging lugs, and the four edges of the wall panel are provided with strip-shaped grooves or strip-shaped protrusions for connecting adjacent wall panels, and the four corners of the floor panel are provided with arc-shaped protrusions matched with the arc-shaped overlap grooves on the vertical columns, and the four edges of the floor panel are provided with strip-shaped grooves or strip-shaped protrusions for connecting adjacent floor panels. wherein the vertical column is selected from a group consisting of a right-angle vertical column, a T-shaped vertical column and a cross-shaped vertical column; wherein the wall panel comprises an outer wall panel and an inner wall panel; and wherein the main body of the right-angle vertical column is a right-angle vertical plate, and the engagement structure of the right-angle vertical column is as follows: ends of two right-angle plates of the right-angle vertical plate are provided with a plurality of hanging lugs for connecting with the outer wall panel, and an arc-shaped overlap groove for overlapping with a floor panel is provided between two right-angle plates; the T-shaped vertical column comprises a T-shaped vertical plate, and a plurality of hanging lugs for connecting with the outer wall panel are provided at ends of the two transverse plates of the T-shaped vertical plate, and a plurality of hanging lugs for connecting with the inner wall panel are provided at an end of the vertical plate perpendicular to the transverse plate of the T-shaped vertical plate, and arc-shaped overlap grooves for overlapping with the floor panel are arranged between the T-shaped vertical plates; the cross-shaped vertical column comprises a cross-shaped vertical plate, and a plurality of hanging lugs for connecting with the inner wall panel are disposed at ends of four plates of the cross-shaped vertical plate, and arc-shaped overlap grooves for overlapping with the floor panel are disposed between adjacent cross-shaped vertical plates, wherein the four corners of the wall panel are provided with hanging posts matched with the hanging lugs, and the four edges of the wall panel are provided with strip-shaped grooves or strip-shaped protrusions for connecting adjacent wall panels, and the four corners of the floor panel are provided with arc-shaped protrusions matched with the arc-shaped overlap grooves on the vertical columns, and the four edges of the floor panel are provided with strip-shaped grooves or strip-shaped protrusions for connecting adjacent floor panels.