A passenger conveyor system and an anti-collision device for step and comb plate. The passenger conveyor system includes a step chain having a plurality of steps, a comb plate and an anti-collision device, the anti-collision device includes an actuating mechanism connected to the comb plate and configured to, when a moving distance of a step adjacent to comb teeth of the comb plate to be engaged in a vertical upward direction of the passenger conveyor system exceeds a preset value, actuate the comb plate to be lifted up from an initial first position to a second position to avoid collision with the step; and a reset mechanism configured to return the comb plate from the second position to the first position after the step travels through the comb plate.