A synchronized motion control system for a double electric bed includes two control devices attached to two electric single beds of the double electric bed respectively. Each electric single bed has a driver circuit and a motor. Each control device has a Hall sensor for generating a Hall signal of the motor, a microcontroller electrically connected with the Hall sensor for generating a rotation number signal according to the Hall signal, and a communication unit electrically connected with the microcontroller. The communication units are electrically connected with each other. The microcontroller of one of the control devices compares the two rotation number signals to generate a difference signal. The motor corresponding to the larger rotation number signal is decelerated according to the difference signal, so as to make the two electric single beds perform synchronized motion.
