The uniform design standard of temporary support structure in building construction has not been published, In case of coupler steel pipe support system, characteristics for the temporary support structure, the standard structure of the system is proposed. It is suggested that the design of temporary support structure should be combined with the present theory of the design of steel structure. The design method of temporary support structure based on equivalent notional lateral loads is proposed. The formula is given, which is verified by tests and is compared with the formula recommended by the present code. The result shows that the formula can meet the requirements of the safety factor, which provides a reference for those concerned with research, design or construction.