The huge investment is required in the construction of the distribution automation system and the grid capacity expansion, however, it is often impossible to complete it in a short time. Hence the grid company should make longterm plans for the development of distribution system. As there is a coupling relationship between distribution automation system planning and grid capacity expansion planning, this paper proposes a new comprehensive planning method to deal with this complex planning problem. Firstly, a mixed integer nonlinear programming (MINLP) model is established with the consideration of the dominant software and hardware infrastructure of distribution system. The objective function of the planning model is to maximize the profits of power grid companies within the planning time range. Then the genetic algorithm is utilized to solve the planning problem of distribution automation system considering grid capacity expansion, which can obtain the best scheme and schedule capacity expansion and construction. The proposed method is tested according to a 24bus system.The performance of the proposed method is compared with another method, which carries out the capacity expansion planning first and then carries out the distribution automation system planning. The results show that the proposed method can greatly improve the profits of power grid companies with a small amount of revenue reduction.