The present invention provides an outer flexible screen mobile electronic terminal and a hinge assembly. A composite supporting layer of a flexible screen is provided between a first side housing and a second side housing; the composite supporting layer comprises a tensile layer capable of being bent and rebounding, and a bendable and flattenable supporting layer of the tensile layer. A hinge comprises a middle supporting portion, a first side connection portion, and a second side connection portion; the outer side of the middle supporting portion is provided with an arc fitting the bending of the flexible screen, and the first side and the second side of the middle supporting portion are respectively provided with gratings; the first side connection portion and the second side connection portion are configured to be in the shape of a comb. The supporting structure of the present invention can flatten and support the flexible screen and fit the bending of the flexible screen, is simple in design and control, improves the sense of touch and protects the flexible screen, and prolongs the service life of the flexible screen.