By reviewing the process of the planning of Suzhou urban rail transit network, qualitative and quantitative analyses are made on the 2020 planning network. After local optimization of line 3 and line 7 and by transposing line 3 and line 5 in the Industrial Park, a new plan of line 3 and line 5 is proposed. The analysis on the project implementation and the comparison of the passenger flow tests indicate that the new plan has better network function. The new line 3 combined with line 8 can act as a loop line.