The invention discloses a method for predicting the life of a concrete structure in a chlorine salt environment based on prototype monitoring data. The method comprises: (1) a section of a reference steel bar having the same material as a structure steel bar is pre-buried when a concrete structure is poured, a conducting wire is led out from the reference steel bar and is connected to a steel bar rust potential monitoring instrument on the outer portion of the concrete structure, whether the reference steel bar rusts is determined by monitoring a rust potential, and the reference steel bar rust starting time t1 is recorded, wherein the distance between the reference steel bar and the surface is d1; and (2) the structure predicting life tc of the structure steel bar is calculated according to a formula. According to the invention, through the deformation treatment on the second law of FICK, the parameters with disadvantages of difficult quantitation and high influence on the life calculation result are eliminated, such that the accuracy of the model calculation is high, and the application operability is strong.