The invention discloses a press-in type pipe shed supporting structure used for a weak stratum tunnel. The press-in type pipe shed supporting structure comprises at least one pipe shed section. Each pipe shed section comprises a plurality of flat steel pipe sets inserted into a soil layer, wherein the flat steel pipe sets are adjacently arranged to form the arched pipe shed section. Each flat steel pipe set is formed by connecting a plurality of flat steel pipe sections end to end in an inserting mode, and the adjacent flat steel pipe sets are connected through buckle assemblies. Through the flat structure of the flat steel pipe sections, the stress area of the steel pipe sections and upper loads is enlarged, and therefore the strength of the supporting structure is improved. Internal reinforcing ribs inside the flat steel pipe sections can improve the vertical pressure bearing capacity of the flat steel pipe sections, and therefore the compressive strength of a pipe shed is improved. The flat steel pipe sets are connected through the buckle assemblies which can be used for connecting the adjacent flat steel pipe sets and also play a role of water stopping so as to prevent underground water from seeping into the pipe shed.