Assembly type self-climbing tower crane supporting beam device and mounting method

The invention discloses an assembly type self-climbing tower crane supporting beam device and an installation method. The installation method comprises the steps that firstly, a first main beam is connected with a semi-finished frame and integrally and horizontally conveyed to a first layer in a cylinder from a hole in the side wall of the core cylinder; the first main beam connecting semi-finished frame entering the core tube is integrally pulled to the first side of the core tube; the first main beam is hoisted and kept balanced; the second main beam is pulled to the second side of the core tube according to the operation steps of the first main beam and is hoisted to keep balance; after the first main beam and the second main beam are adjusted and aligned, an anti-torsion beam is installed between the first main beam and the second main beam, and the first main beam and the second main beam are connected into an integral supporting beam; and after auxiliary equipment is laid, the supporting beam is lifted