This paper firstly introduces the concept of life cycle cost and the meaning of life cycle cost estimation, secondly analyzes the advantage and disadvantage of the conventional estimation method. By introducing the principles and methods of wavelet and wavelet transformation, a wavelet neural network structure applicable to equipment development expense is built. Finally, data simulation combined with airplane Life Cycle Cost (LCC) is done, and the simulation results show that the method mentioned in this paper is feasible and practicable.