To deal with assembly sequence planning in airplane manufacturing, a novel assembly sequence planning method based on memetic algorithm is proposed. Assembly planning model is constructed by using the constraint matrix and the non-orthogonal interference matrix, and fitness function is established by the sum of difference of assembly direction and tools between aircraft components. Assembly planning is globally searched in the non-interference solution space, and inorder traversing binary tree sort algorithm is adopted to transform from optimal assembly planning solution to feasible solution. Optimal solution is local searched in the feasible solution space by crossover and mutation operations. Assembly planning process of the aircraft cabin door is illustrated to prove the feasibility of the proposed model, and compared with the genetic algorithm, the proposed algorithm is more effective.