The invention belongs to the field of 
pharmacology, and relates to stapled-RGD polypeptide, and applications thereof in 
tumor targeting delivery. Multifunctional targeting polypeptide molecule stapled-RGD with high combination activity with 
integrin and 
biological membrane barrier penetration capacity is designed and prepared based on 
binding peptide cyclization technology; and preparation of 
fluorescein, drugs, and high molecule carriers modified by the multifunctional targeting polypeptide molecule stapled-RGD, and applications of the 
fluorescein, the drugs, and the high molecule carriers in 
tumor imaging and construction of 
targeted therapy targeted drug delivery systems are disclosed. It is shown by results that specific uptaking of model drugs carried by stapled-RGD by positive cells, tumor 
mimicry vessels, and tumor ball tissues of expressed 
integrin is realized, higher 
tumor targeting capacity, imaging functions, and membrane barrier 
cell penetration capacity are achieved; nano 
targeted drug delivery systems constructed by the high molecule carriers modified by stapled-RGD can be used for delivering carried model drugs to target tissues, antitumor 
drug effect is improved obviously; and stapled-RGD possesses a promising application prospect in mediating drugs, nano 
targeted drug delivery system membrane barrier penetration, 
active target searching, tumor diagnosis, and 
targeted therapy.