A plug-in type busbar for connecting with a relay or a breaker includes an insulating housing and a plurality of conductive busbar parts insulated from each other in the insulating housing. Two interface sets are provided on two ends of the busbar respectively. One interface set on one end of one busbar can be inserted in the other interface set of the other bus bar. The busbar is connectable with adjacent busbars through the interface sets at both ends thereof. At least an electrical connection is formed between the adjacent two busbars after the adjacent two busbars are inserted each other. When a longer busbar is demanded, an extended structure can be obtained by simply connecting two busbars together, and a connection of the busbars can be completed by connecting the insulating housing in a plugged manner.