Disclosed is a penetration and assembly structure for a flexible circuit board with a hinge assembly. With a pre-folding line formed on a pre-prepared flexible circuit board serving as a center line, a connection section of the flexible circuit board is folded to a terminal distribution section, and then, the connection section and an extended sheet are wound up in a direction towards the terminal distribution section to form the connection section into a rolled body with the extended sheet wrapped around the rolled body to provide an effect of protection. The rolled body is then inserted through a bore of a hinge assembly so that after the rolled body completely passes through the bore of the hinge assembly, the extension section of the flexible circuit board is located in the bore of the hinge assembly and the first end and the second end are respectively set at opposite ends of the bore of the hinge assembly. In other applications, a reinforcement plate is included to reinforce the terminal distribution section of the flexible circuit board.