The family grid-connected photovoltaic system is an important part of the solar energy industry planning and its energy optimization scheduling model is an important research topic. In the light of the uncertainty of photovoltaic output in the system, it is expressed in the form of interval. Taking the minimum cost of system operation as the objective function, while taking into account the necessary constraints of system such as power balance constraints and others, a basic energy optimization model of family grid-connected photovoltaic systems is established. A robust optimization framework is applied to transform the constraint condition containing uncertain variables in the basic energy optimization scheduling model into deterministic constraints, so as to establish a robust optimal energy scheduling model for family grid-connected photovoltaic systems. The improved firefly algorithm is used to solve the model. The simulation example shows that the system operation scheme obtained by proposed model has good robustness in the actual operation and is able to reduce the economic risk of the system. This work is supported by Key Program of National Natural Science Foundation of China (No. 51337005).