The efficacy and safety of paclitaxel (Pac) coated capsules in the treatment of lower extremity lesions in stent after lower extremity angioplasty stenting are concerned. In order to achieve this goal, Pac is used as the model drug, and it is adsorbed into chitosan hollow nanospheres (Chi-HN) by adsorption equilibrium method, so as to obtain drug loaded nanospheres (Pac-Chi). The results of Chi-HN are observed by TEM and SEM. The solid state of PAC is characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and Fourier transform infrared spectrometer (FT-IR). The release properties of drug loaded nanospheres are tested. The biocompatibility of nanospheres is tested by cytotoxicity test. The inhibitory effect of PAC nanospheres on cancer cells before and after treatment is compared. In the treatment trial of LEAS patients, the pharmacokinetics of drug loaded nanospheres is analyzed, the blood glucose metabolism in patients is tested, and the preoperative and postoperative vascular stenosis degree, minimum diameter and other data are compared. In the experiment, the release rate of Pac in Pac-Chi is slow. The characterization of drug loaded nanospheres confirms that Pac exists in amorphous state in Chi-HN. Meanwhile, Pac-Chi can inhibit the proliferation of cancer cells. The pharmacokinetic test shows that Pac-Chi can improve the efficacy of Pac in patients, and the blood glucose concentration of patients remains relatively stable. In the experimental observation of in-stent restenosis (ISR), the immediate success rate of patients using Pac-Chi nanospheres with interventional procedures is as high as 100%, and there is no adverse cardiovascular phenomenon during the treatment.