The invention discloses a design method of a reinforced concrete beam and column structure and the reinforced concrete beam and column structure, and relates to the technical field of reinforced concrete structures. The reinforced concrete beam and column structure comprises a first beam, second beams and supporting columns. The design method comprises the steps that the designed reinforcement rate of the first beam is obtained; and when the designed reinforcement rate of the first beam is larger than the maximum reinforcement rate, under the premise of guaranteeing that the sectional area ofthe first beam is unchanged, the designed width of the first beam is increased, and the designed height of the first beam is decreased. According to the design method provided by the invention, underthe condition of guaranteeing that the sectional area of the first beam is unchanged, the designed height of the first beam is decreased, and the designed width of the first beam is increased to decrease the reinforcement rate of the first beam; and increasing of the building material using quantity of the whole beam and column structure is avoided, increasing of the project cost is avoided, and meanwhile the clearance size of a building adopting the beam and column structure is further increased.