The parallel assembly of rectifier modules includes a plurality of rectifier modules connected in parallel, a switch for switching-in and switching-out of the rectifier modules, an assembly frame, being provided therein with a switch accommodating space and a rectifier module accommodating space; a DC bus bar, being arranged at the top of the assembly frame; a plurality of groups of connectors, being fixed at one end close to the back side of the assembly frame; an AC copper bar, being fixed at one end close to the front side of the assembly frame; an extended copper bar, being fixed at one end close to the back side of the assembly frame.