Reducing the impact scope of power failure caused by power outage and preserving the power supply should be both taken into account for microgrid emergency energy management after the failure of electricity supply in distribution network. This paper presents an emergency energy management strategy based on robust optimization for commercial building microgrid consisting of photovoltaic-battery system, and controllable loads regulation scheme is proposed after obtaining the inputs of controllable loads, following the principle of “first adjustment, then cutting off”. The proposed strategy embraces the thought of rolling optimization. Besides, based on robust optimization model, weighting factors are introduced to weigh the importance of reducing the impact and preserving power, and uncertainty is set up to adjust the influence of uncertain factors on the problem. Comprehensive results obtained from comparative analysis, sensitivity analysis and uncertainty analysis have shown that the proposed strategy is effective in adjusting the inputs of controllable loads to reach the desired goals by changing weighting factors and uncertainty flexibly. Moreover, real-time charging rate of electric vehicles and real-time ambient temperature of air conditioners can be obtained from controllable loads regulation scheme.