The invention discloses a kind of high strength ultrathin float glass, comprising the following ingredients: 60-62 wt% of SiO2, 12-15 wt% of Al2O3, 0.4-1.1 wt% of CaO, 6.5-8 wt% of MgO, 11-13 wt% of Na2O, 3-5 wt% of K2O, 1-1.2 wt% of Li2O, 0.5-1 wt% of ZnO, 1-1.5 wt% of B2O3, wherein, the total amount of SiO2, B2O3 and Al2O3 accounts for 73-76.5 wt%, the total amount of SiO2 and Al2O3 accounts for 72-75 wt%, the total amount of MgO and CaO accounts for 7-9 wt%, the total amount of Li2O, Na2O and K2O accounts for 15-18 wt%, and the molar ratio of n(K2O) to n(Na2O) is 0.15-0.3. The high strength ultrathin float glass has the characteristics of high chemical stability, high hardness, and large intensity, and simultaneously satisfies the special molding demands for ultrathin float glass.