A new near-infrared noninvasive method of detecting the glucose from human skin tissue interstitial fluid is presented. The skin tissue structure is refined, and the papillary layer containing a small amount of blood separated from the lower area of the dermal layer and the surface layer are used as the main objects. The wrist curved side is selected as the detecting part. And the average probe depth, the main absorption position, the average photon path length, the outputting energy and the fraction of absorbed energy in each skin tissue layer are calculated by the Monte Carlo method based on the above. The results show that both the average probe depth and the main absorption area are located in the papillary layer. The average photon path length is long enough and less energy is absorbed by the stratum corneum and the dermis when the distance between detector and the source is 0.6 mm. Thus the optimum source-detector distance of 0.6 mm is determined and the optical fiber detector is designed. The uniqueness of the method is that the spectral information from the epidermis and papillary is captured without the interference from the rich blood containing lower dermis, which is good for the near-infrared noninvasive blood glucose detection and provides a theoretical basis for the follow-up work.