A sensor system with brightness change is characterized in that the peripheral convex edge of an LED inner sleeve is provided with two pairs of clamping columns which extend towards the back and are arranged at equal intervals, and embedding grooves for clamping the corresponding clamping columns are correspondingly formed in the back shell of a bead body. A sensor element is arranged at the lowerpart of the LED table and can perform longitudinal rotation corresponding to the LED table. The overall configuration structure of the sensor element comprises that the lower portion of the LED tableis provided with a sensor positioning opening, the sensor element comprises a sensor body and a sensor connecting end, the sensor body is located below the LED bead body, and the upper portion of thesensor connecting end is clamped and positioned in the sensor positioning opening. The defects that in the prior art, the projection radian and the sensing radian area of a sensor provided with an LED are not large, the projection area of the LED is constrained, the arrangement is complex, a bead body back shell frequently slides off through an LED sleeve, and the standard operation of the LED isnot facilitated are effectively avoided.