The invention relates to a stage lighting system which especially comprises a lens array, a focusing lens and an LED array, wherein the lens array comprises a plurality of lenses and corresponds to the LED array so as to collimate the light output by LEDs into subparallel light; the focusing lens focuses a light beam formed by converging the subparallel light to a light exit port of the lighting system; and the LED array comprises a plurality of LEDs packaged on a heat radiating substrate. The N rows of LEDs are arranged by following the rule that the N rows of LEDs are equally divided into aleft half part and a right half part, wherein each LED chip arranged in the left half part respectively rotates in one direction by an angle preset for the LED chip; the arranging angle of each LED chip in the right half part is the same to that of an LED chip in the left half part, which is symmetrical to the LED chip in the right half part with respect to the center point of the array. The square output light spot of the LED array can be converted into a circular output light spot by using the stage lighting system, so that the light utilization ratio of the system is increased.