According to design principles of precast concrete beams from《Technical specification for precast concrete structures》(JGJ1-2014)and《Technical standard for assembled buildings with concrete structure》(GB/T51231-2016), combining with drawing collection for National Building Standard Design《Assembled concrete structure connection node construction》(G310-1~ 2)analyzing structural measures of precast concrete beams and superimposed layers, summarizing precast concrete beams information as the general information, type information, geometry information, primary beam and secondary beam node information, reinforcement information, embedded parts information and other information, exploring general detailing rules of components and their connection, and through general descriptions and general construction details, realizing structural standardization. Specify the local coordinate system of the beam on the component floor plan, through the code to express the precast concrete beams, instead of the detailed drawing of the component, referring to drawing rules and standard detailing drawings to express the superimposed layer, to achieve the ichnographic representing of concrete composite beam.