The present invention provides an expandable fusion device capable of being installed inside an intervertebral disc space to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion. In one embodiment, the fusion device includes body, a first endplate, and a second endplate, a middle ramp piece, a stem, and two ramp pins. The middle ramped piece is operable to move to generate lordotic expansion of the first and second endplates followed by parallel expansion. The fusion device is operable to be deployed down an endoscopic tube.