In order to improve the construction technology of municipal pipeline and meet the increasing requirements of pipeline construction, a miniature EPB (earth pressure balance) shield with diameter of 1.22 m is designed and manufactured. The control requirements, functional characteristics and working principles of the hydraulic system are studied, and detailed calculation is carried out. And then the technical problems of the hydraulic system induced by the miniature shield and the relevant solutions are analyzed. The driving system and thrusting system of the cutterhead is simulated and analyzed by software AMESim. The research results show that: (1) When the load varies, the rotating speed of the cutterhead hardly varies (for about 4.8%), which indicates that the cutterhead driving system has good robustness. (2) The thrusting speed can be controlled in real time under uniformly fixed load and uniformly varying load conditions; the response speed is fast, and there is only a small overshoot and the maximum is 12%, which shows that the thrusting system has good speed control performance. The simulation results are good and have practical guiding significance.