LED light attenuation automatic compensation circuit, device and system

The utility model provides an LED light attenuation automatic compensation circuit, device and system. The LED light attenuation automatic compensation circuit comprises a brightness detection control circuit, a single-chip microcomputer control circuit, a PWM power supply PWM signal isolation circuit and a single-chip microcomputer. The brightness detection circuit comprises a photoresistor, and the brightness detection control circuit is connected with a pin 15 of the single-chip microcomputer through the photoresistor; the single-chip microcomputer control circuit is connected with the single-chip microcomputer. A pin 18 of the single-chip microcomputer is connected with a PWM signal isolation circuit of the PWM power supply, a target brightness value of the LED lamp is written into the single-chip microcomputer, the light dependent resistor collects brightness information of the LED lamp and writes the brightness information into the single-chip microcomputer, the single-chip microcomputer compares and de