Abstract: In the irrigation area which adopts the flow measuring instrument,there are inevitably a lot of error in the process of measuring and calculating the water because of the section measured or person factors.Some illogical phenomena occur now and then.For example,sometimes the water measured on the upriver station is more than the lower station,and sometimes the water calculated between the stations is more or less obviously inaccurate.By using the revised simplex method of the linear planning theory,a model for adjusting water is proposed to adjust water of the illogical measuring stations and increase the precision of the statistics of allocated water and allocation regulation.Through application to Weishan irrigation area,it is shown that the model has a good effect.The decisive method in theallocation regulation of irrigation area realizes transformation from the practical qualitative analysis to the scientific quantitative analysis.So water management becomes more scientific.