With the rigidly enforcing day by day of regulation of environmental protection, the production of the clean fuel has already become the urgent task that world oil refining industry has faced. The fluid catalytic cracking is in order to the oil refining device that produced mainly petrol and diesel oil, gave consideration to the industrial chemical raw materials. Especially in our country, 80% of the petrol comes from the catalytic cracking, and the content of the olefin is up to 40%-60% in the catalytic cr...