With the accumulation of time, the data is sharply increased in provincial environment system. And there are many different kinds of monitoring data and the description of the different environmental indicators varies. As the monitoring data is growing every minute, the complexity of the data is increasing. The data fusion technology is a method of processing data in big data technologies, which can process data, analysis data and make trend analysis through transfer, correlation and fusion compute data from multiple sensors. The using of ETL, MapReduce and D-S evidence reasoning algorithm can increase the correlation data, so reduce the size of the data.