In order to effectively control the cutter replacement risk and improve the efficiency of seacrossing shield tunneling, the scalereduced disc cutter wear experiment and rock abrasion experiment of different rocks are carried out, by taking complex strata of seacrossing section on Xiamen Rail Transit Line No. 3 for example. And then the power exponential relationship between the wear rate of cutter material and CAI value of rock abrasion is revealed; and the method for predicting the consumption of cutter by measuring the CAI of rock samples of the proposed project is established. Finally, the method mentioned above is applied to the prediction of disc cutter replacement distances of shield in intermediatelyslightly weathered granite of Xiamen Rail Transit Line No. 3, and the prediction results are 50 m for edge disc cutter and 215 m for front disc cutter; base on which the advices for disc cutter replacement positions and methods are provide. The results can provide reference for similar projects in the future.