In this paper, we study a new model for predicting the reacted fraction of hydriding in La(Fe,Si)₁₃ compounds. This model is simple and practical, which offers the reacted fraction of hydrogen absorption as a function of time and temperature explicitly. The basic principle and reaction mechanism of hydrogen absorption of alloy materials are briefly introduced. Besides, the “characteristic absorption time” as a new concept has been introduced, which directly reflects the hydrogen absorption rate of the alloy, and the smaller the characteristic reaction time, the faster the hydrogen absorption rate. Application of the Chou model, quantitatively exploring the hydrogen-absorbing reaction characteristics of La_0.7Pr_0.3Fe_11.5Si_1.5 and La_0.7Pr_0.3Fe_11.5Si_1.5C_0.2 alloys. At the same time, the change of temperature will also affect the hydrogen absorption characteristics of the alloys, the relationship between the reacted fraction of hydrogen and the temperature is obtained by the model equation, indicating that the higher the temperature, the smaller the characteristic reaction time, the faster the hydrogen absorption rate of the alloys.