The invention discloses a tower crane rotation control system and method. The tower crane rotation control system comprises a motor and a frequency converter. The motor is used for driving a tower crane rotary mechanism in a tower crane. The frequency converter is used for driving the motor to operate, determining the tower crane rotary speed of the tower crane rotary mechanism according to the motor operating speed and a preset estimation model, and adjusting the motor operating speed according to an input given speed and the tower crane rotary speed so as to enable the tower crane rotary speed to reach the given speed. The tower crane rotation control system and method have stable control, high efficiency, no need for eddy current brake to assist speed adjustment and low cost; and sinceonly an ordinary inverter and a motor are arranged, devices are less, and fault points are less.