Main products in Ethylene-plant were ethylene oxid(EO), monoethylene glycol(MEG) and diethylene glycol(DEG).The condition adjusting of more EO or MEG and DEG were created by device design. In the recent years，there were more changes on product price. In order to realize enterprise benefit maximization,the devices potential was digged, the product structure was adjusted without increasing raw materials. The requirements on special equipment and operation were put forward in combination with the change of product structure adjustment of process operating paraments.