The present invention provides a high-modulus glass fiber composition, a glass fiber and a composite material therefrom. The glass fiber composition comprises the following components expressed as percentage by weight: 55-64% SiO2, 13-24% Al2O3, 0.1-6% Y2O3, 3.4-10.9% CaO, 8-14% MgO, lower than 22% CaO+MgO+SrO, lower than 2% Li2O+Na2O+K2O, lower than 2% TiO2, lower than 1.5% Fe2O3, 0-1.2% La2O3, wherein the range of the weight percentage ratio C1=(Li2O+Na2O+K2O)/(Y2O3+La2O3) is greater than 0.26. Said composition can significantly increase the glass elastic modulus, effectively inhibit the crystallization tendency of glass, decrease the liquidus temperature, secure a desirable temperature range (ΔT) for fiber formation and enhance the fining of molten glass, thus making it particularly suitable for production of high-modulus glass fiber with refractory-lined furnaces.