The chaos improved Newton iterative method finding all real solutions of nonlinear equations was proposed and the forward displacement analysis on the 25th nine-link Barranov truss was completed. Four constrained equations were established by vector method with complex numbers according to four loops of the mechanism and four supplement equations were also established by increasing four variables and the relation of sine and cosine function. The established eight equations are that of forward displacement analysis of the mechanism. Combining improved Newton iterative method with chaotic sequences, chaos improved Newton iterative method based on utilizing new type chaos system introduced by Chen to obtain locate initial points to find all real solutions of the nonlinear questions was proposed. The numerical example was given. The result shows that all real solutions have been quickly obtained, and it proves the correctness and validity of the proposed method.