Abstract: The crankshaft is an important power transmission component in high-speed marine diesel engines. During operation, it is subject to complex periodic cyclic alternating stresses such as gas pressure, motion inertia force, bending moment, and torque, making it highly prone to fatigue failure. Therefore, to achieve a high-reliability design of the key structural parameters of the crankshaft, this paper proposes a crankshaft structural optimization scheme based on the Kriging model. Firstly, the Latin hypercube sampling theory is used to sample the structural parameters of the crankshaft transition fillet within a limited range. Secondly, combined with the sampling results, a Kriging prediction model is built to complete the optimal prediction of the key structural parameters of the single-throw crankshaft. Finally, the NCode analysis module in the finite element analysis software is used to predict the service life of the optimal structure, verifying the reliability and rationality of the research scheme.