The present disclosure provides a PCB fixing structure. The PCB fixing structure includes a housing, a PCB accommodated in the housing, and a top cap covering the housing. The housing has a side wall provided with at least two protrusion portions. The protrusion portion defines a connecting hole. The PCB defines at least two first through holes. The top cap defines at least two second through holes. The PCB fixing structure further includes at least two connecting pieces. Each of the connecting pieces is configured to pass through one of the second through holes, one of the first through holes and one of the connecting holes in sequence so as to fix the top cap and the PCB to the housing. The present disclosure further provides an electronic cigarette including the PCB fixing structure and a fixing structure for a PCBA control board of an electronic cigarette.