A vascular puncture sealing device includes a tube unit (1) and a sealing unit (2). The tube unit (1) includes an inner tube (11) and an outer tube (12). The inner tube (11) includes a first compartment (S1) therein. The outer tube (12) includes a second compartment (S2) therein. The inner tube (11) is slidably received in the second compartment (S2). The sealing unit (2) is coupled to an end of the inner tube (11). The sealing unit (2) includes an abutting portion (22) and an expansion portion (23). The abutting portion (22) includes a first face (22a) and a second face (22b) opposite to the first face (22a). The abutting portion (22) further includes a through-hole (221) extending from the first face (22a) through the second face (22b). The expansion portion (23) includes a chamber (S3) intercommunicated with the through-hole (221) of the abutting portion (22).