A new uranyl silicate [(K,Na)4Cl2][(UO2)6(Si2O7)2F2] (1) was obtained from melt in evacuated silica tubes. The crystal structure of 1 is orthorhombic, Pnma, a = 36.8677(7), b = 7.7946(2), c = 19.1931(4) Å, V = 5,515.5(2) Å3. It represents a microporous framework comprised of UrO5 and UrO4F pentagonal bipyramids and Si2O7 disilicate groups. The framework contains two types of channels with the size of 8.14 × 8.66 and 6.38 × 4.42 Å2; the smaller ones host the potassium cations while the larger ones contain more complex alkali-chloride species.