A pipe joint structure, comprising: a joint body; a support seat, wherein a first end of the support seat is sleeved on outside of the joint body, a second end of the support seat is disposed to be separated from the joint body, and an accommodating cavity is defined between an inner wall of the support seat and an outer wall of the joint body; a housing, wherein a first end of the housing is sleeved on outside of the support seat and engaged with the support seat, a second end of the housing is disposed beyond the second end of the support seat, so that a contraction cavity is defined between an inner wall of the housing and the outer wall of the joint body; an insertion opening through which a pipe can be inserted is defined between the joint body and the second end of the housing, the insertion opening communicates with the accommodating cavity via the contraction cavity, an end of the contraction cavity close to the insertion opening is a small opening end, and the other end of the contraction cavity away from the insertion opening is a large opening end; and an elastic member, wherein the elastic member is sleeved on the outside of the joint body and disposed in the contraction cavity; a passage through which the pipe can pass is defined between the elastic member and the joint body; characterized in that an outer wall of the support seat is provided with a plurality of engagement grooves and guiding grooves, the engagement grooves are spaced apart along a circumferential direction of the support seat, the guiding grooves communicates with the engagement grooves respectively, and a side of each of the guiding grooves away from each of the engagement grooves penetrates through an end surface of the second end of the support seat; a wall of the housing is provided with a plurality of engagement plates, and the engagement plates are capable of engaging with the engagement grooves through the guiding grooves. a joint body; a support seat, wherein a first end of the support seat is sleeved on outside of the joint body, a second end of the support seat is disposed to be separated from the joint body, and an accommodating cavity is defined between an inner wall of the support seat and an outer wall of the joint body; a housing, wherein a first end of the housing is sleeved on outside of the support seat and engaged with the support seat, a second end of the housing is disposed beyond the second end of the support seat, so that a contraction cavity is defined between an inner wall of the housing and the outer wall of the joint body; an insertion opening through which a pipe can be inserted is defined between the joint body and the second end of the housing, the insertion opening communicates with the accommodating cavity via the contraction cavity, an end of the contraction cavity close to the insertion opening is a small opening end, and the other end of the contraction cavity away from the insertion opening is a large opening end; and an elastic member, wherein the elastic member is sleeved on the outside of the joint body and disposed in the contraction cavity; a passage through which the pipe can pass is defined between the elastic member and the joint body; characterized in that an outer wall of the support seat is provided with a plurality of engagement grooves and guiding grooves, the engagement grooves are spaced apart along a circumferential direction of the support seat, the guiding grooves communicates with the engagement grooves respectively, and a side of each of the guiding grooves away from each of the engagement grooves penetrates through an end surface of the second end of the support seat; a wall of the housing is provided with a plurality of engagement plates, and the engagement plates are capable of engaging with the engagement grooves through the guiding grooves.