Aimed at the present technical difficulty in multiple anchor installation in deep hole, study was made on the installation technology and the installation device, and composite anchor installation device with spline rod and spherical bit was developed. The technical problems were effectively resolved, such as anchor installation and grouting at the bottom in ultra-deep hole in collapsing, block-falling and hole diameter-shrinking formation. The paper detailed the rotary composite anchor installation device with spline rod and spherical bit about the structure, working principle and application effect.