In fatigue life prediction, many models fail to account for the impact of various factors, such as small load strengthening effect, loading sequence and real-time damage state. In this paper, a new nonlinear fatigue life prediction model has been developed, which a load action factor is introduced into Ye's toughness dissipation energy model. The action factor combines the small load stress ratio, stress amplitude ratio, and fatigue real-time damage function into an exponential function with multiple powers. This model effectively considers the interaction between loads, loading sequence, real-time damage and the small load strengthening effect. The modified fatigue life prediction model has been tested using data of commonly metal materials, such as 45-gauge steel and 16Mn, under two or more variable amplitude loads. The comparison between experimental and predicted values shows that the new nonlinear fatigue life prediction model can more accurately predict the remaining fatigue life for different materials under multistage variable amplitude loading. Moreover, the model does not require additional parameters and can be easily implemented in practical engineering applications.