Photon properties of transmission and spatial distribution in fiber optic tapers were modeled and stimulated by Monte Carlo modelling. Photons distribution and intensities distribution after photons transmit through tapered optic fiber were presented. According to the stimulation,most photons after propagation through the fiber optic taper distribute in the centre of detector,and the number of photons detected by detector was decreased as the distance between the detector point and the centre point of the detector increases. If the fiber optic tapers have certain taper ratio and different length,the distributions of photons propagating through them were similar and the intensity reduced with the growth of the length of fiber. The study results provide an important evidence of design and application of fiber optic tapers.