A stage light fixture with high-accuracy rotary positioning includes a supporting member and a pivoting member pivoted to the supporting member. The pivoting member has at least one light source for generating a lighting effect and is driven to rotate by at least one flat motor. The flat motor includes a stator generating a magnetic field by energization, and a rotor sleeve on the stator and driven by the magnetic field. The pivoting member is fixedly connected with the rotor, and the supporting member is fixedly connected with the stator; or the pivoting member is fixedly connected with the stator, and the supporting member is fixedly connected with the rotor. With respect to the conventional rotating shaft motor, no transmission assembly is provided, a transmission error thus can be avoided to achieve more accurate positioning, and a height of the motor can further be reduced.