The earthwork allocation plan is an important part of the earthwork construction plan. The existing research on the earthwork allocation plan ignores the non-linear influencing factors and has a weak ability to guide the construction. In this paper, the nonlinear earthwork allocation model is transformed into a function extreme value problem, and an improved simulated annealing algorithm is proposed to solve it. Taking the airfield expansion project of Hannan Airport as an example, the superiority of the improved simulated annealing algorithm is proved through the comparison of various heuristic algorithms, and the solution performance of the improved simulated annealing algorithm under different problem scales is analyzed.