Crack repair by microbiological precipitation of CaCO3 provides a new method in the seepage and plugging of the underground engineering. A field experiment was designed to verify its efficiency. Four measures were taken.(1)The trough outside horizontal crack can prevent seriflux from penetrating into the soil, and the grouting pressure can be obtained by liquid height.(2)The slant holes were drilled to grout the vertical crack.(3)Bacteria liquid and urea Ca(NO3)2 solution were brushed on the surface of the crack by turns.(4)The mechanical drilling and the PVC pipes were chosen for grouting in soil. The repair effect were tested and evaluated by test of injecting water, observation after the rain, ultrasonic testing and geological radar detection，and the results show that the repair is efficient.