We use the thermal analysis module of ANSYS software to establish the finite element model of transversal seepage in the permeable lock chamber，study the distribution characteristics of transversal seepage in the permeable chamber under maintenance condition，and discuss the effect of vertical seepage control facilities in different positions. The results show that the distribution of seepage pressure head and seepage gradient are not uniform. The distribution of pressure head along contour lines can be divided into rapid loss section，loss retarding section and slow loss section according to the rate of pressure head loss. The seepage gradient at the chamber bottom increases from the symmetric axes to the end. The seepage gradient at the bottom of the chamber wall increases from one side with the sheet pile to the other side without the sheet pile. When the sheet piles are in the same length，the back sheet pile can significantly reduce the seepage pressure at the bottom of chamber wall compared with the front sheet pile，while the front sheet pile has a better control effect on the exit gradient of chamber and the seepage gradient at the bottom of chamber wall.