The present disclosure provides a method for predicting a three-dimensional frost heaving deformation of a formation during freezing construction of a metro tunnel and relates to the field of metro tunnel construction. The method includes: firstly determining a freezing construction position, obtaining soil horizon parameters of undisturbed soil within a range of a freezing wall, determining thermophysical and mechanical parameters of soil, layering a soil horizon above the freezing wall according to soil horizon properties thereof and existing buildings (structures), and determining a horizon where a frost heaving influence range exists; subsequently calculating an unsteady temperature field of a single freezing pipe and a radius of a freezing front; then calculating an inner radius and an outer radius of the freezing front after closure of the freezing wall according to a tunnel excavation type, and calculating a frost heaving region; and finally calculating a frost heaving displacement.