A cap manipulator and a cap assembly are provided. The cap manipulator includes a first airbag member, a second airbag member, and an airstream channel structure therebetween and enabling inner spaces of the first airbag member and the second airbag member to be communicated. If the second airbag member is squeezed, a volume of the first airbag member is greater than that of the insertion space, and if the second airbag member is not squeezed, the volume of the first airbag member is smaller than or equal to that of the insertion space.
