Imaging fiber plays an important role in medicine, industry, aerospace and other fields because of its excellent flexibility, especially in the application of optical fiber endoscope in medicine. Optical fiber image transmission system is usually composed of imaging objective, imaging fiber and image sensor.At present, the number of pixels in cameras can reach millions or even tens of millions, but the number of pixels in optical fibers is usually only a few hundred thousand.Therefore, the resolution of the system is limited by the resolution of the imaging fiber itself, and the imaging resolution of the whole system basically depends on the number of pixels that the imaging fiber can transmit. At present, the imaging fiber bundles on the market have either high resolution but small total cross-sectional area, or large cross sectional size but fiber diameter up to ten microns. This phenomenon results in insufficient pixels and small image area of high resolution image fiber, while large cross section can not reach high resolution due to technological limitations. To solve the problems, this paper proposes a multi-aperture high-resolution imaging technology based on imaging fiber array, which uses the imaging fiber array and image Mosaic technology to break through the bottleneck of improving pixel number. The number of pixels in the system can be increased by using high resolution and small cross section imaging fiber arrays. Combined with the characteristics of overlapping imaging of microlens array, the problem of information loss caused by direct imaging of imaging fiber array can be solved and the integrity of optical fiber array imaging can be realized.This method is expected to increase the number of pixels in optical fiber image transmission system to millions of order of magnitude and improve the resolution of the system. The imaging fiber is designed to be arranged 6×8, and the microlens array is designed based on the imaging fiber array. There are two groups of aspherical lenses made of PMMA material, and the imaging fiber array and the two groups of microlens arrays have uniform positions. Add a telecentric objective lens in front of the microlens array as the main lens of the image transmission system to solve the problem of complete overlap of adjacent subgraphs caused by direct imaging of the microlens array. The focal length of the lens is 10.1 mm, the aperture coefficient is 6.3, and the field Angle is 88°. The simulation results show that both the main lens and the microlens array can meet the performance requirements of the imaging fiber, and the object information can be successfully transmitted to the imaging fiber. The modulation transfer function value of the system can reach more than 0.5 at 50 lp/mm, without weakening the quality of the primary image, and meet the resolution requirements of the imaging fiber. Experimental results show that the system contains 400 000 effective pixels and the system resolution is 40 lp/mm.The image is clear and complete, which proves that the design of the imaging system has a good feasibility, and has an important practical reference significance for improving the resolution of the optical fiber image transmission system.