Abstract: A circuit board structure for preventing high-frequency signal leakage and a manufacturing method thereof are provided, in which the circuit board structure body includes a signal layer, a first ground layer, and a second ground layer. A first shielding film structure and a second shielding film structure are respectively covered on the upper surface and the lower surface of the circuit board structure body and are aligned and adhered, so that the upper surface, the lower surface and the entire board edge of the circuit board structure body are wrapped by the first shielding film structure and the second shielding film structure. The first shielding film structure includes a first conductive metal layer and a first insulating layer, and the second shielding film structure includes a second conductive metal layer and a second insulating layer.