Fixing structure for printed circuit board (PCB) of set top box

The utility model provides a fixing structure for a printed circuit board (PCB) of a set top box. The fixing structure comprises a housing, the printed circuit board (PCB), a front panel, a back panel, a left-side support and a right-side support. The left-side support is provided with a left clamping groove, a left positioning pillar and left fixing holes; and the right-side support is provided with a right clamping groove, a right poisoning pillar and right fixing holes. The printed circuit board (PCB) clamps the left-side support and the right-side support together through the left clamping groove and the right clamping groove. The left-side support is inserted and fixed to the back panel through the left positioning pillar, and the right-side support is inserted and fixed to the back panel through the right positioning pillar. The front panel is fixed to the left-side support and the right-side support through the left fixing holes and the right fixing holes. The housing is inserted into a sealing groove