The invention relates to a dual-sensitivity amphiphilic 
polysaccharide-
doxorubicin conjugate.According to the conjugate, hydrophobic antitumor 
drug doxorubicin is introduced in a 
polysaccharide framework through a connecting arm containing a 
disulfide bond and a 
hydrazone bond, so that the 
polysaccharide-
doxorubicin conjugate has an amphiphilic property, can be self-assembled into a nano-
micelle in water and directly used for tumor treatment, and can also be physically loaded with an antitumor 
drug to be used for antitumor treatment.The conjugate is mainly characterized in that after the nano-
micelle reaches a focus, the 
disulfide bond in the connecting arm can be degraded specifically by high-concentration reduction substances in focus cells, and meanwhile the 
hydrazone bond in the connecting arm can be degraded in a special pH environment of the focus, so that the 
micelle is degraded, the 
drug is quickly released, and the 
treatment effect is improved; the antitumor drug is loaded in two 
modes of chemical conjugation and physical 
package, and therefore the joint 
treatment effect is achieved.The polysaccharide conjugate and a pharmaceutical composition can be used for injection or 
oral administration or external administration, can remarkably improve 
antitumor activity, and provides a new thought for development of the antitumor drug.