Diffuse reflectance spectroscopy is widely applied in non-invasive detection of human tissue. Depth and transmission path of detecting photons may influence the sensitivity and accuracy of spectral detection. The conventional fiber-optic probes with parallel illumination-collection fibers vertical to skin tissue cannot selectively collect scattered photons from specific penetration depth. For the purpose of human components sensing, the present work designs the specific fiber probes configuration with certain illumination-collection angle or half-ball lens coupled to improve the detection efficiency of dermis. Based on three layers tissue model, Monte Carlo simulation is modified and applied to evaluate the penetration depth of detected photons, percentage of effective photons, effective information loading and detection sensitivity of dermis with each fiber probes. The results indicate that probes proposed in this paper improve the detection efficiency and sensitivity of dermis and the effect of the changes of tissue structure of non-target layer and optical parameters on it is small.