A corrugated tube installation rack used for culvert construction comprises a rail frame, L-shaped fixed plates and a triangular support, wherein the rail frame is transversely arranged on the bottom edge of a culvert, the L-shaped fixed plates are arranged at the two ends of the rail frame, and the triangular support is installed on the rail frame in a sliding mode. The L-shaped fixed plates comprise two bottom plates and two vertical plates perpendicular to the bottom plates, and the bottom plates and the vertical plates are respectively provided with installation holes. The rail frame is transversely arranged on the bottom edge of the culvert, and a vertical rod, a stair and the rail frame are fixed to form a triangle together; when an arc corrugated tube unit needs to be fixed, the triangular support is pushed below the arc corrugated tube unit needing to be fixed through the rail frame, the height of the vertical rod is adjusted until the top end of the vertical rod compresses the arc corrugated tube unit needing to be fixed, then the stair in the triangular support is adjusted and rotated along the top end of the vertical rod until the bottom end of the stair makes contact with an upper frame of the rail frame, and the stair is fixed through a brake device arranged at the bottom of the stair.