The invention relates to a method for predicting resilience of a bar subjected to two roll straightening, and belongs to the technical field of two-roll straightening machines. The method comprises the followings steps: firstly, determining the offset of a stress neutral layer when the rod is subjected to straightening; then, determining a deformation-hardening coefficient and tension-
compression stress distribution according to different straightening processes and deformation characteristics of rods in different specifications; finally, determining the model for predicting rebound
bending moment and straightening rebound deflection by combining a
pure bending and rebound theory, wherein the rebound deflection
delta is related to the following variables of R, sigma<t>,
lambda, xi, psi, kappa, I, E, L, B, n, R0, Rw, P and tau; R represents a rod
radius; sigma<t> represents the
yield limit;
lambda represents a hardening coefficient; xi represents an elastic region ratio; psi represents a neutral layer offset
radius ratio; k represents an anti-bend rate; I represents rod section
moment of inertia; E represents modulus of elasticity; L represents the distance between the two end points in three-point bending; B represents a plastic coefficient; n represents a hardening index; R0 represents an initial bending
radius; Rw represents an anti-
bend radius; P represents straightening force; tau represents a correction coefficient. According to the method, a straightening and deformation process can be truly reflected, and the straightening theory can be perfected; resilience in the straightening process can be accurately predicted, and bases for the roll
shape design and process parameter establishment are provided.