The invention discloses a method for evaluating flow impact of a reactor core outlet of a sodium-cooled fast reactor, which comprises the following steps of: carrying out geometric modeling by using Solidworks according to an actual structure of the reactor core outlet of the sodium-cooled fast reactor, and carrying out fluid domain and solid domain subdivision; performing grid division on a fluiddomain in a grid division function of computational fluid mechanics software, setting physical properties and boundary conditions of liquid metal sodium in a fluid computational domain, and performing transient flow field calculation by adopting a high-precision large eddy simulation method; performing condition setting and mesh generation on the solid domain in finite element analysis software;using a multi-physical field coupling platform MpCCI for transmitting flow field parameters obtained through computational fluid mechanics software to finite element analysis software, and making solid structure mechanics calculation in the finite element analysis software; and finally, evaluating the flow impact influence of the reactor core outlet of the sodium-cooled fast reactor through mechanical analysis of a flow field and a solid structure.