The invention discloses an internal driving method of a three-wheel turning body of a spherical robot. The spherical robot comprises a spherical shell, a detector support, a detector, a circuit module, a supporting plate, a battery compartment and an actuating device, wherein the detector support is provided with a bull-eye wheel, and the actuating device comprises a Mecanum wheel and a drive motor. The internal driving method comprises the first step of obtaining a target parameter, the second step of controlling the orientation of the spherical robot, the third step of controlling three wheels to stop running after the orientation of the spherical robot faces a target position, the fourth step of controlling a number two wheel and a number three wheel to conduct uniform velocity and inverted running, the fifth step of controlling the three wheels to stop running after the circuit module receives a signal that the spherical robot arrives at the target position, and at this time, the spherical robot precisely arrives at the target position. According to the internal driving method of the three-wheel turning body of the spherical robot, the problems that in the prior art, the movement is not flexible and convenient, the movement efficiency is low, and the monitoring capacity is greatly limited by environmental facilities are solved.