The invention relates to a height-adjustable supporting pipe for an oil delivery pipe. The height-adjustable supporting pipe comprises a base of a square-pyramid structure. The upper surface of the base is provided with a groove. The supporting pipe further comprises a supporting base arranged in the groove. The supporting base is of a cuboid structure. The upper surface of the supporting base is provided with a semicircular pipe groove. The supporting pipe further comprises a hoop arranged in the pipe groove. The hoop comprises two semicircular shells connected to each other through a hinge. The hinge is fixed to the bottom of the pipe groove. The supporting pipe further comprises flat plates horizontally connected to the two ends of the pipe groove respectively. One side of each flat plate is provided with a cuboid groove. The two semicircular shells connected through the hinge are arranged in the cuboid grooves in the flat plates in a sliding mode respectively. The supporting pipe further comprises a lock catch arranged at one end of any one semicircular shell. According to the height-adjustable supporting pipe, the semicircular shells are arranged in the cuboid grooves in the flat plates in the sliding mode respectively, and the two semicircular shells are connected through the hinge, so that the size of the hoop can be adjusted, and petroleum pipes of different sizes can be fixed.