The utility model provides a shore protection engineering shallow underground drainage system for unfavorable geology. The drainage system comprises a water drainage subsystem and a shallow underground drainage subsystem which are arranged on a slope from top to bottom in a staggered mode; the shallow underground drainage subsystem comprises a plurality of uniformly-distributed blind ditches; the blind ditches are arranged in an inverted Y-shaped mode from the slope top to a water shortage platform; the water drainage subsystem comprises an open trench and an interception ditch which are vertically arranged and communicated with each other; the interception ditch is arranged on the slope top in the direction of the interception ditch; the open ditch is arranged on a slope between the slope top and the water shortage platform; an anti-filter cushion layer and a surface covering structure are arranged on the surface of the slope from bottom to top; the blind ditches are densely arranged; the section of the blind ditch is in an inverted trapezoidal shape; the inner bottom surface and two sides of the blind ditch are laid with non-woven fabrics; and the blind ditch is backfilled with finger stones. By the shallow underground drainage system, the water drainage capacity of shallow groundwater of the bank slope after implementation of the construction can be improved, and the stability of the slope is enhanced.