The invention provides a friction-type self-balancing up-and-down opening and closing mechanism for an outdoor giant wall curtain system. According to the friction-type self-balancing up-and-down opening and closing mechanism, two motors which are fixed to guide rail bottom plates on a wall surface, and the motors synchronously drive LED lamp bars through driving steel wire ropes. The steel wire ropes are arranged to be connected with winding drums in a friction manner, and therefore the two ends of each LED lamp bar are released from a middle contraction state; gravity centers of all the LED lamp bars are kept unchanged in the releasing process, self balancing is achieved, and energy is saved.