Expanded spinal fusion cage

An expanded spinal fusion cage, comprising:

• an outer frame;
• a sliding block set having a middle sliding block located within the outer frame, wherein the middle sliding block is located between two outer sliding blocks;
• a screw rod penetrating through and combined with the outer frame, wherein the screw rod is screwed with the middle sliding block, such that the middle sliding block is moved in translation in the outer frame and simultaneously expands the two outer sliding blocks by rotating the screw rod;
• two curved surface elements located outside the outer frame and combined with the two outer sliding blocks respectively, wherein each of the two curved surface elements has a wing plate;
• and
• two vertebral arch screws penetrating through and combined with the two wing plates, wherein the middle sliding block has an upper slope surface facing an upper opening of the outer frame, and the middle sliding block has a lower slope surface facing a lower opening of the outer frame, wherein the two outer sliding blocks are abutted against the upper slope surface and the lower slope surface respectively by a slope surface.