The invention relates to a rotating mechanism of a hydraulic multifunctional pile driver. The rotating mechanism of the hydraulic multifunctional pile driver comprises a walking mechanism, a main machine and a stand column which are sequentially connected from bottom to top, wherein the stand column is connected with a main fixture through a hydraulic oil cylinder; the main machine is connected with the stand column and transmits power through a worm and gear mechanism to achieve rotation of the stand column in a horizontal direction; the worm in the worm and gear mechanism is driven by a hydraulic motor, and the inner ring of the worm gear of the worm and gear mechanism is detachably fixedly provided with a thread bushing which is threadedly connected with a spindle; the spindle is detachably fixedly connected with a main machine base; the worm is fixedly connected with the stand column and the machine body through bearing pedestals. Compared with the prior art, the rotating mechanism of the hydraulic multifunctional pile driver has the advantages of being capable of achieving self-locking action during rotating construction of the stand column, ensuring the construction precision and stability, enabling the pile driver to be applicable to various working conditions, saving additional pile foundations erected during corner construction and improving the working efficiency; the rotating connecting devices are all in a detachable mode, so that convenience and rapidity during equipment maintenance and repair can be obtained.