The invention provides an adjustable supporting device for a petroleum engineering pipeline. The adjustable supporting device comprises a baffle plate, a force receiving piece, a strong outer supporting spring, a contact plate, an anti-sliding piece, a supporting spring, a connecting shaft, a fixing piece, fixing teeth, connecting blocks and a clamping piece; the bottom end of a moving part is installed in an upper part in an embedded manner, and the bottom end of the moving part is connected with the bottom end in the upper part through the strong outer supporting spring; and the connecting blocks are mounted on the two sides of the top-end side edge of the moving part in a welding manner, and the outer end of the clamping piece is connected with the top ends of the fixing teeth. A main body plays a role of being fixedly installed under the soil, and then the upper part and an inserting part are installed so that more labor can be saved during installation, a cross-shaped insertion groove is formed on the upper portion of the main body and used for fixing the insertion part, and then the upper part can be fixedly installed through the insertion part; and the sliding edge is used for making contact with a limiting piece, so that the limiting piece can be retracted.