The invention provides an internal-focusing high power focusing lens, relates to the focusing lens and aims to solve the problems that an existing high-power laser large-aperture focusing lens fails to move precisely, precise focusing is unavailable, and multiple beams of high-energy lasers are difficult to focus to a minimal cross section in space. The internal-focusing high power focusing lens comprises a lens shielding sheet assembly, a lens replacing unit assembly, an X-direction position adjusting assembly, a Y-direction position adjusting assembly and a Z-direction position adjusting assembly. The lens shielding sheet assembly is installed on the lens replacing unit assembly. The lens replacing unit assembly is installed on the X-direction position adjusting assembly. The X-direction position adjusting assembly is used for driving a lens driving assembly to move in the X direction. The X-direction position adjusting assembly is installed on the Y-direction position adjusting assembly. The Y-direction position adjusting assembly is used for driving the X-direction position adjusting assembly to move in the Y direction. The Y-direction position adjusting assembly is installed on the Z-direction position adjusting assembly. The internal-focusing high power focusing lens is suitable for focusing the focusing lens.