According to matter element and extension set theory,an extension elements model on coal and gas outburst proneness prediction was built,and an extension clustering method for the prediction was brought forward.

Application of extension method in the oil pump and oil mouth production at the processing center;

Strategy formation for urban house pulling down and migration using extension methods;

Evaluation of crack width of continuously reinforced concrete pavement based on extension method;

On the basis of a study of the Forecast of the international container Transportation, the writer chose to use the mode - buiding mechanism for expansion and collection forecast on domestic container transportation, builds an element mode for expansion and collection mechanism, and makes a forecast on domestic container shipping.

Aiming at thesituation that the load forecasting of power system mais have certain errors,double extension gather-type model and calculating way are put forward.