This paper takes Gan Fuxi model as the theoretical basis, firstly verifies its feasibility for predicting the density and elastic modulus properties of glass fibers, and then deduces the density and elastic modulus additivity coefficients of TFe2O3 of the iron series glass fibers system and predicts the density and elastic modulus of this system, which lays a foundation for the Gan Fuxi model to be used in the design of the composition of the iron series glass fibers and prediction of their properties. The results of the study show that VFe=6.8142NTFe2O32−79.6131NTFe2O3+276.0759 when 3.5 % ≤ NTFe2O3 ≤ 5.6 % and VFe=43.4 when 5.6 % ≤ NTFe2O3≤ 7.17 %, and the prediction relative errors are 0 ∼ 2.15 %. When NTFe2O3 ≤ 9 %, the modulus of elasticity additivity coefficient of TFe2O3 is ETFe2O3×10−5=−19kg/cm2, and within the studied components, 73.9 % of the component relative errors fall in the range of 0 ∼ 10 %. Display omitted