Building foundation pit supporting beam component convenient to recycle and construction method

The invention relates to the technical field of building foundation pit supporting beams, in particular to a building foundation pit supporting beam component convenient to recycle and a construction method.The building foundation pit supporting beam component convenient to recycle comprises a standard knot longitudinal supporting beam, a standard knot transverse supporting beam and a bearing plate, and a transverse supporting opening is formed in the transverse middle of the standard knot longitudinal supporting beam; one end of the standard knot transverse supporting beam penetrates through the transverse supporting opening and is fixed through a bolt, and the two longitudinal ends of the standard knot longitudinal supporting beam are each provided with a first telescopic knot supporting beam through a bolt and a connecting block; through the standard knot supporting mechanism, the foundation pit supporting function of longitudinal and transverse structures is achieved; the problem that a traditional founda