Abstract
This paper proposes the use of lifts 89C51 microcontroller control movement. the entire Lift control system by braking control,weigh, altimeter, alarm, Ping-place and the SCM system. weigh, altimeter which is used as input system transmit the weight and the height signal to the microcontroller through the sensor, the braking control which is used as output system control the rotational of motor or whether to issue a warning signal. And 89C51 microcontroller which is the core of the whole system is used to deel with the height and weight signal which comes from the input system and output the control signal.