It is one of the perplexing questions of the development of American university in recent years that the graduating rate is low,every universities devoted to promote the graduating rate,some school put forward effective measures and can be rated as the example in the similar level school.

The system of graduating beforehand, breakthrough in teaching management system, foretelling the basic standard of measuring whether students can graduate is changing gradually from laying stress on studying time into studying quantity and quality of students.

Loose Enrolment,Strict Graduation is the basic principle of many distance education institutions,and the graduation rate is an important factor determining the products quality in those schools.

The measures to keep the system stable by power support and generator trip are studied.

The optimum analyses of the raising condition and the raising efficiency are made by means of theoretical analyses of basic equations in the process of raising liquid in the paper.