The invention discloses an amphiphilic ternary 
polymer brush and a nano 
capsule. The amphiphilic ternary 
polymer brush has the following general formula, wherein A is 
polymer main chain, B is lipophilic polymer 
side chain, C is photo-crosslinked polymer 
side chain, D is hydrophilic polymer 
side chain, and the side chains B, C and D are randomly grafted onto the main chain A; and the nano 
capsule is prepared through dispersing the amphiphilic ternary 
polymer brush into an oil-water two-phase 
system, and then performing light crosslinking reaction or reaction initiated by light. The amphiphilic ternary 
polymer brush solves the difficulty that the particle size of the 
capsule can not be adjusted and controlled effectively by using the conventional segmented copolymers, and the size of the prepared photo-crosslinked nano capsule is easily adjusted and controlled; the nano capsule prepared by the 
emulsion self-
assembly method is simple in operation and easy to use in large-scale preparation; the prepared hollow nano capsule is large in 
casting quantity; the photo-crosslinked nano capsule provided by the invention is stable, and according to the light crosslinking method, nontoxicity and safety are reliazed, and the 
environmental protection is realized. The amphiphilic ternary 
polymer brush has the following general formula: A-g-(B-r-C-r-D).