Sudden water inrush encountered during operation of the open-type TBM may lead to dangers, and then grouting of sealing slurries is often the main means to control the geological disaster. On the basis of analyzing the shortcomings of the existing slurries, the formula of the sealing slurry suitable for open TBM method was developed, and then was optimized by orthogonal tests. The final formula is as follows: water cement ratio 0.59, tartaric acid 0.25%, hydrolytic polyacrylamide solution 3% and sodium aluminate 1.6%. Under the condition that the controllability (pumping period, etc.) met the requirements, the properties of the optimized formula, including water precipitation, compressive strength were tested and the laboratory simulation test was also done. The stone developed from the orthogonal tested formula provided good compressive strength and impermeability, meeting the needs of the field. The pump can stop in a short time after injecting the controllable slurry at the inflow point. Compared with the traditional slurry, the amount of slurry used for plugging leakage can be greatly reduced. The results show that the controllable formula has a good control effect on the water inrush danger encountered in construction of tunnels in the province, and can meet the actual construction needs.