Drilling apparatus with guiding of guide rod

The invention relates to a drilling apparatus with guiding of a guide rod. The drilling apparatus comprises a housing (9) and a drive shaft (8) arranged in the housing (9). A blind hole with a guide rod (81) is formed in the lower end of the drive shaft (8); guide holes (82) are formed in the left side and the right side of a cylinder body part (62) of a transmission cylinder (6), thereby realizing the sliding fit with the guide rod (81) of the blind hole. And an inner spline is arranged at the inner side of the cylinder body part (62) of the transmission cylinder (6), thereby realizing cooperation with an outer spline arranged at the outer side of a radial expanding part (71) of a drilling rod (7).