A modular multilevel converter-unified power quality conditioner (MMC-UPQC) structure comprises a UPQC series connection container, a UPQC low-pressure tank container, a UPQC parallel connection container, a UPQC high-pressure tank container, a single-phase isolating transformer, a UPQC bridge arm reactor and a filter reactor. The single-phase isolating transformer is arranged at the position close to a feed-out bus; the UPQC series connection container, the UPQC low-pressure tank container and the UPQC parallel connection container are sequentially shaped like a - shape and arranged on one side of a cable channel; the UPQC high-pressure tank container and a UPQC are vertically arranged and positioned on the other side of the cable channel; and the UPQC bridge arm reactor and the filter reactor are combined in a three-layer stacking mode to be a series connection part and a parallel connection part and arranged on two sides of the UPQC low-pressure tank container respectively. The MMC-UPQC structure is compact in structure, can run directly safely reliably under the outdoor environment and is small in occupied space, wire connection between devices is simple, the electrical and civil construction period is short, and the cost is reduced.