With the application of photovoltaic/battery system such as family photovoltaic/battery system more and more widely, its economic dispatch becomes an important issue. In order to solve the problem of the optimal operation of the family photovoltaic-storage system, a real-time economic dispatch method is proposed, which is based on the charging and discharging strategy of energy storage. In this paper, firstly a model is established to evaluate the energy storage charging cost of the current period and the discharge yield at the beginning of the next period, secondly a real-time economic dispatch method is constructed according to a principle in economics that, when the marginal cost equals the marginal benefit, the comprehensive benefit is the largest. This method can meet the requirement of the real time scheduling of the family photovoltaic-storage system, and at the same time maximize the economic efficiency, therefore the proposed method can maximize the elimination of subjectivity when formulate the behavior strategy of storage in real-time economic dispatch energy storage, so as to enhance the advantages of real-time economic dispatch. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.