The present invention discloses a steel wire welding lightweight grid frame and a building member. The steel wire welding lightweight grid frame is a three-dimensional flat-plate network structure made by welding steel wires, and is formed by welding a middle cone structure core layer, an upper plane steel wire mesh sheet and a lower plane steel wire mesh sheet. According to the present invention, the lightweight grid frame forms a small-size quadrangular pyramid system, such that the structure rigidity is increased, characteristics of good stability, designability and multifunctionality are provided, the parts can be subjected to scale production through the factory and can be assembled and connected at the construction site so as to eliminate a lot of tedious manual operations and long construction period, and the steel consumption is less and the weight is light so as to substantially reduce the cost. With the application of the technical scheme of the present invention in the building member, the reinforcing steel bar keel effect can be provided, the steel wire welding lightweight grid frame and the additional reinforcing steel bar or section steel and concrete are fused to form the excellent whole mechanical performance, and the bearing capacity, the stability and the anti-seismic performance of the building member can be increased.