Abstract: Mud cake often occurs to earth pressure balance during tunneling. To reduce the mud cake cleaning risk in soil chamber and economic loss caused by shied stop, a visualization system of soil chamber based on camera shooting technology, programmable logic controller control technology, mechanical structure design, and hydraulic principle is designed and developed. The factory and field experiments show the malfunction of the system developed is mainly caused by water and soil pressure, mud, and dark environment. Accordingly, targeted designs and improvements have been conducted to improve the workability of the system, realizing good applicability of the system in severe environment.

Key words: earth pressure balance shield, soil chamber visualization, mud cake, mirror flushing, light junction temperature, spray head block