A scanless and lensless 3D endoscopic imaging method based on a coherent fiber bundle (CFB) is proposed. Compared with conventional endoscopic imaging method, the proposed method uses the end face of a bare fiber bundle as a probe and does not require integrating any low-light-level mechanical components. Therefore, the proposed method provides a simple structure, small volume, and easy miniaturization. Moreover, it combines synthetic aperture lidar (SAL), broadband linear frequency-modulated lidar, and digital holographic lidar. A broadband linear frequency-modulated laser generated an active illumination signal, and the CFB collected and transmitted the scattering echo of a target. Simultaneously, based on off-axis digital holography, a high-speed CCD array camera recorded the echo signal. Finally, SAL data processing method is used to reconstructed a 3D image of the target. The mathematical model of the 3D endoscopic imaging system is established, and the corresponding data processing method is detailed. Theoretical and simulation results show that the proposed method overcomes image pixilation caused by the inherent structure of the CFB and has the ability of precise transversal and longitudinal 3D imaging perceptions.