The invention discloses a reinforced concrete grid frame structure with phosphogypsum as a wall material and a method for building the same. During the construction of a reinforced concrete building structure which has less than or equal to 15 floors and a total height of less than or equal to 45 meters, a reinforce concrete part of a whole load bearing wall of the reinforced concrete building structure is built in a reinforced concrete grid frame structure; meanwhile, a floor system of each floor of the reinforced concrete building structure is built in a reinforced concrete rib cross large panel floor; spaces between all reinforced concrete load-bearing members of the reinforced concrete grid frame structure are filled with phosphogypsum to serve as walls, and all reinforced concrete load-bearing members are wrapped by the phosphogypsum; and thus a reinforced concrete grid frame structure with phosphogypsum as a wall material is built. The reinforced concrete grid frame structure has the advantages of good shearing rigidity, strong earthquake-resistant capacity, light self-weight, good energy-saving thermal-preservation, heat-insulation and sound-insulation performance, large-size room, flexible room division and so on and is particularly applicable to low, mediate and low-rise dwelling buildings and office buildings.