The utility model relates to the technical field of power converters, in particular to a slot box for a patch board, an anti-drop patch board and an anti-drop plug, the slot box for the patch board comprises a front side plate, a bottom plate and a rear side plate, and the front side plate and the rear side plate have the same structure and are distributed at intervals front and back; the anti-drop patch board comprises a patch board groove box and a patch board, and the patch board is arranged in the mounting groove; the anti-drop plug comprises a plug body, a front limiting tongue and a rearlimiting tongue, the plug body is inserted into the patch board, and the front limiting tongue is arranged on the front side of the plug body corresponding to the lower position of the front limitingtongue. The plug is reasonable and compact in structure and ingenious in conception, the plug body is prevented from slipping off the patch board through the cooperative use of the groove box for thepatch board, the anti-falling patch board and the anti-falling plug, and the plug has the characteristics of reliability, stability and safety.