Two new alkali/alkaline-earth metal pyrophosphate fluorides, A2Mg2P2O7F2 (A = K, Rb) have been synthesized, structurally analyzed, and characterized for the first time. They both crystallize in the Pbcn space group and show similar crystal structures. Their structures contain 1[Mg2O7F3]∞ chains made up of edge-sharing MgO4F2 octahedra and 2[A2O11F4]∞ layers built by face-sharing [A2O11F4] clusters, which are bridged by isolated P2O7 units to construct a 3D framework. It's worth noting that A2Mg2P2O7F2 (A = K, Rb) are the first pyrophosphate fluoride in the A-Mg-P-O-F (A = alkali metal) system. Furthermore, the optical measurements of the title compounds show that they all possess UV absorption cutoff edges. First-principles theoretical studies were conducted to understand the electronic structures.