a movable chassis;

a chair;

a chair backrest;

at least one first folding mechanism, installed between the movable chassis and the chair; and

at least one second folding mechanism, connected between the chair and the chair backrest;

wherein, the at least one first folding mechanism and the at least one second folding mechanism are connected in series and both have a four-rod linkage structure, and when the collapsible wheelchair is switched from a folded state to an open state or from the open state to the folded state, the at least one first folding mechanism and the at least one second folding mechanism are configured to move simultaneously;

wherein, each of the first folding mechanisms comprises a first support rod, a second support rod, a first connecting base and a second connecting base, wherein a first end of the first support rod and a first end of the second support rod are both hinged with the first connecting base, and a second end of the first support rod and a second end of the second support rod are both hinged with the second connecting base, and the second connecting base is fixedly connected with the chair;

wherein, each of the second folding mechanisms comprises: a fourth support rod, a fifth support rod and a sixth support rod;

wherein the collapsible wheelchair further comprises a first extension end, a first end of the first extension end is fixedly connected with the second end of the second support rod, a second end of the first extension end is hinged with a first end of the fourth support rod, a second end of the fourth support rod is hinged with a first end of the sixth support rod, a second end of the sixth support rod is fixedly connected with the chair backrest, a first end of the fifth support rod is fixedly connected with the chair, a second end of the fifth support rod is hinged with the chair backrest; and

wherein, under the folded state of the collapsible wheelchair, the movable chassis, the chair, and the chair backrest are stacked in parallel with each other.