The present invention relates to the technical field of
geological survey, and provides a method for directional
coring along a large-angle curved path, comprising the following steps: S1, selecting an appropriate drilling path on the basis of the depth and span of a river bottom to be traversed, so as to ensure that the drilling path passes through the entire river bottom and reaches a mountain on an opposite
bank; S2, using a first
coring tool to
drill a first borehole section in a downward-inclined direction from a
road surface, and during the drilling, a
wireline coring mechanism inside the first coring tool continuously
cutting off and retrieving core samples; S3, retrieving the first coring tool upon completion of the drilling of the first borehole section, and mounting a casing in the first borehole section; and S4, replacing the first coring tool with a second coring tool, a
pilot bit passing through the casing and continuing drilling, the
pilot bit continuously changing the drilling direction under the weight of a coring
drill rod, and a
wireline coring mechanism inside the second coring tool continuously
cutting off and retrieving core samples. In the present invention, the drilling direction of the
drill bit can be changed during drilling and coring, thereby facilitating directional traversal across deep-
cut valleys and retrieval of core samples in mountainous and
canyon regions.