Karst collapse is one of the key issues in shield tunneling through karst formations. It will not only cause damage to oil and gas pipelines， but will also lead to oil and gas leaks， damage to the ecological environment and threaten the lives and property of people living along the route. This paper is aimed at the characteristics of cave development in karst strata encountered by shield tunneling at a site in Yongzhou， Hunan Province. The formulation of a basalt fibre bentonite-cement paste with good rheological and mechanical properties was preferred. In-situ grout filling and reinforcement experiments with basalt fibre bentonite-cement paste were carried out， and the reinforcing effect of the grouting material was tested by means of borehole coring and indoor experiments. As a results， the cores obtained from the boreholes are dense and have a strong cementation strength. The core take rate meets 80% of the construction requirements. The 28d unconfined compressive strength of the grouted consolidation bodies drilled to a depth of 6~7m was small， averaging 0.32MPa， due to the influence of groundwater. But the cores were relatively intact. The 28d unconfined compressive strength of the grouted consolidation at a drilling depth of 7~8m increased by approximately 5.36 times compared to the grouted consolidation at 6~7m. The strength of the grouted solids reinforced by in-situ grouting with basalt fibre bentonite-cement paste is greater than the strength index required for construction， effectively guaranteeing the safety of shield crossing in karst areas.