The invention discloses a method for manufacturing a bendable fluorescent screen by taking a mica sheet as an observing surface and application thereof. The method comprises the following steps: (1) processing the mica sheet; (2) cleaning the mica sheet; (3) preparing fluorescent powder coating liquid; (4) coating fluorescent powder; (5) curing at a low temperature. The method has the advantages that (1) the bendable fluorescent screen can be used for observing the motion locus of an electron beam in a three-dimensional space under the action of an external magnetic field or electric field in a vacuum environment, and can be applied to occasions on which bending is needed; (2) the problem of easiness in causing air leakage since the fluorescent screen of the conventional vacuum device needs to be taken as a part of a glass shell of the vacuum device is solved, and the reliability of the vacuum device is enhanced; (3) by adopting a screen printing method, high yield is achieved, a small number of chemical reagents are consumed, convenience is brought to large-scale production, and meanwhile uniform and consistent laminating brightness of the fluorescent screen can be ensured; (4) the design of a Y deflecting plate is simplified, the design difficulty of an electronic optical system for a vacuum display device is lowered, the number of parts in the electronic optical system is reduced, and the production cost is reduced.