This invention relates to a light emitting device and its manufacturing method, in which, the method includes: providing at least a CB set with multiple luminescent packaged pieces, a first undetermined power input end and a second undetermined power input end, and the packaged pieces are connected with the two undetermined power input ends, each of which has at least two first weld panels and the two first weld panels of the two input ends are isolated to each other, the first input end is selected as the power input region for inputting foreign supply signals, then the two first weld panelsof the second input end are electrically connected.