The invention discloses an AC contactor mounting structure for a high-voltage reactive compensation device. The AC contactor mounting structure comprises three phases of AC contactors, a left mounting base, a middle mounting base, a right mounting base, a left fixing base, a middle fixing base and a right fixing base, wherein the left mounting base, the middle mounting base and the right mounting base are correspondingly located on the left fixing base, the middle fixing base and the right fixing base respectively; correspondingly matched arc-shaped grooves are formed in the left mounting base, the middle mounting base, the right mounting base, the left fixing base, the middle fixing base and the right fixing base respectively; threads are respectively arranged on the walls of the arc-shaped grooves and are screwed with screw rods respectively; the three phases of AC contactors are correspondingly located on the left mounting base, the middle mounting base and the right mounting base respectively; slots are respectively formed in the left mounting base, the middle mounting base and the right mounting base; positioning posts are inserted into the slots respectively; and baffle plates are inserted among the corresponding positioning posts respectively. The AC contactor mounting structure is simple; and when one phase of AC contactor is damaged, the damaged AC contactor can be maintained and changed by only rotating the corresponding screw rod, drawing out the mounting base on which the AC contactor is located, and then dismantling the corresponding positioning post and baffle plate, so that the operation is simple and fast; and the work efficiency is improved.