There are lot factors to effect discharge coefficient （or efficiency coefficient）curve . As for curve configuration in formula，it is diffi鄄 cult to select function form and the undetermined coefficient calculation is complex. Through statistical analysis of data ，this paper proved that the relationship between data rules and polynomial function is correct，the relation between data rules and compound function is correct，and variable substitution rules are correct. Using these relationships and replacing rules ，more functional form were developed to meet the general formula configuration requirements.