The invention discloses a compound vibrating well-drilling tool which comprises a sleeve, a vibrating short joint, a vibrating short joint chuck, a screw motor, a conversion short joint connected with the lower end of the screw motor, an annular disc sleeved at the upper end of the conversion short joint, a hydraulic cylinder installed at the lower end of the conversion short joint, an impact short joint arranged in an inner cavity of the hydraulic cylinder and a torque transmitting short joint, wherein the vibrating short joint, the vibrating short joint chuck, the screw motor, the conversion short joint, the annular disc, the hydraulic cylinder, the impact short joint and the torque transmitting short joint are arranged in sequence from top to bottom. The well-drilling tool can be installed at different positions in a well-drilling column, the drilling column generate axial and circumferential high frequency compound vibration through the tool, and phenomena including 'pulling press' and 'stick slip' in the large-inclination well drilling process are eliminated, thereby remarkably improving mechanical drilling speed, prolonging the service life of a drill bit and reducing well-drilling cost.