A system for predicting the service life of a liquid crystal panel of a monitoring and control device can monitor the work state of the liquid crystal panel by monitoring the accumulated lightening time of backlight in order to predict the service life of the liquid crystal panel. The system includes a backlight control circuit, a memorizer, a processor, and a communication management panel. In practical application of the liquid crystal panel of the monitoring and control device, a power supply of liquid crystal backlight is controllable; a base pin of the processor can control power-on and power-off of an MOS transistor to achieve light-on and light-off of the liquid crystal screen. During determination of the service life of the liquid crystal screen, when the MOS transistor is powered on, software enables a timer to calculate the power-on time of the MOS transistor and accumulates the power-on time (in seconds), and then the accumulated result is stored in the memorizer E2PROM; the accumulated time is the total work time of the liquid crystal screen and can be read by the system at any time to monitor the work state of the liquid crystal screen; and when the work time approaches a service life threshold of the liquid crystal screen, the communication management panel can give a tip for replacement, and can give an alarm through an indication lamp.