Power consumption analysis isSinstructiveSto formulate effective energy-saving scheme in buildings. This paper proposes an analysis model of power consumption analysis in buildings based on K-means clustering and FP-Growth association rules. It has been some inspiration of strong association rules through cluster analysis and association analysis to the total energy consumption of commercial buildings, sub metering data and weather temperature, giving the theory support for improving the optimal operation strategy of building equipment. The proposed method was applied to the energy consumption analysis of an office buildings in Shanghai. The results proved that the presented technique is of the validity and practicability.