Abstract: The existing four totally different theoretical formulae for partially penetrating well in phreatic aquifer with different tube lengths under submerged conditions connot better solve the problem caused by unceasing change of phreatic level drawdown in a real project. The diving layer is divided into two parts along the maximum drawdown of water level, and by dopting the integral transformation method, the formulae for steady flow of partially penetrating well in phreatic aquifer are a obtained under constant flow condition when the tube length and submerged conditions are different. Then on this basis, a program is developed by using Delphi and Matlab to analyze the characteristics of well flow. Finally, it is proved that it can be applied to practical projects through a foundation pit example. The research results show that: (1) the formulae can be degenerated to Dupuit formula for penetrating well in phreatic aquifer under certain circumstances, and approximate analytical solution can be obtained under certain circumstances; (2) the self-developed program can be adopted to calculate resistance coefficient and flow automatically and quickly under different conditions of partially penetrating well in phreatic aquifer, which provides many conveniences for analyzing well flow; and (3) It is feasible to apply the proposed formulae in foundation pits with water-resistance enclosures and dewatering.