The invention relates to the field of theft prevention and particularly relates to an anti-theft system for an outdoor electrical cabinet. The anti-theft system comprises an inner box body and an outer box body, wherein a central processing unit, a buzzer and a wireless communication module are mounted on the internal sidewall of the inner box body, an inner box door is fixed on the front end face of the inner box body, and fans with driving motors are uniformly mounted on the outer side face of the inner box door; infrared emission detectors are arranged on the inner top face and inner bottom face of the outer box body, an intelligent dome camera is fixed at the center of the top face of the external box body, and an outer box door with a password lock is fixed on the front end face of the outer box body; the central processing unit is separately electrically connected with the buzzer, the wireless communication module, a driving motor controller mounted in the inner box body, the password lock, the infrared emission detectors and the intelligent dome camera, the driving motor controller is electrically connected with a driving motor, and the central processing unit is in wireless communication with an intelligent monitor terminal through the wireless communication module. According to the anti-theft system for the outdoor electrical cabinet, thieves are effectively prevented from proceeding criminal activities through effective multiple protective measures.