A pet tent support structure includes a top-portion support, a bottom-portion support, and two lateral supports capable of being sequentially folded towards the bottom-portion support. The top-portion support includes two horizontal rods capable of being respectively folded towards the lateral supports. The bottom-portion support is a rectangular structure formed by four horizontal rods. The two lateral supports each comprise a horizontal rod and two vertical rods respectively connected to two ends of the horizontal rod. The vertical rods are connected to the bottom-portion support via bottom-portion connection members, and the bottom-portion connection members of the two lateral supports have a difference in height therebetween. The pet tent support structure can be folded easily and quickly, and the size of the structure after folding is small and occupies a small space, thus enabling convenient storage and carrying.