The invention relates to a method for evaluating the acid rain erosion degree of concrete. According to the method, the acceleration test of simulation of acid rain erosion in a laboratory is carried out to acquire the change rules of the mass, acidification depth, rupture strength and compressive strength of concrete eroded by acid rain; then mathematical fitting analysis is carried out to respectively establish relation equations between the acidification depth and the change rate of mass, between rupture strength and the change rate of mass, and between the compressive strength and the change rate of mass, i.e., X(t)=f(M(t)), Rf(t)=f(M(t)), and Rc(t)=f(M(t)); and the acidification depth, rupture strength and compressive strength of the concrete can be calculated by substituting the mass data of an on-site exposed concrete test piece in an actual acid rain erosion environment or the mass data of a concrete test piece under other simulated acid rain erosion conditions in the laboratory into the equations. Thus, the acid rain erosion degree of the concrete can be evaluated.