The invention relates to preparation and application of a reducing sensitive nano-
micelle, belonging to preparation and application of an amphiphilic block 
polymer. A hydrophilic section and a hydrophobic section of the amphiphilic block 
polymer are connected with each other by a reducing responsive 
sulfur-
sulfur bond; the nano-
micelle is formed by self-assembling; the reducing sensitive nano-
micelle consists of a shell and an inner core, wherein the shell is a hydrophilic 
polymer, and the inner core is a 
hydrophobic polymer; the hydrophilic section of the amphiphilic block polymer is 
polyphosphate, the hydrophobic section of the amphiphilic block polymer is poly(benzyl glutamate), and the hydrophilic section and the hydrophobic section of the amphiphilic block polymer are connected with each other by the reducing responsive 
sulfur-sulfur bond. The reducing sensitive nano-micelle has the advantages that the 
drug-loaded nano-micelle is difficult to dissociate outside the cells or in the blood, so that the 
drug encapsulated in the nano-micelle is enabled to be stable; once the nano-micelle enters the 
cancer cell, the sulfur-sulfur bond can be disconnected by 
glutathione which is a reducing matter in the 
cell, so that the nano-micelle is rapidly dissociated, the anti-
cancer drug encapsulated in the nano-micelle can be rapidly and effectively released out, and an 
effective treatment effect is achieved; the reducing sensitive nano-micelle overcomes the defects that the drug is easy to leak 
in vivo, low in transport efficiency, slow in 
intracellular release speed, and the like.