The aim of this study was to develop an optically deviated focusing-based variable depth-of-focus (DOF) oriented optical coherence microscopy (OCM) system to improve the DOF in high-resolution and precise focused imaging. In this study, an approach of varying beam diameter using deviated focusing was employed in the sample arm to enhance the DOF and to confirm precise focusing in OCM imaging. The optically deviated focusing technique was used to vary the focal point and DOF by altering the sample arm beam. The efficacy of the variable DOF imaging approach utilizing an optimized sample arm was confirmed by tissue-level imaging, where OCM images with varying DOF were obtained using deviated focusing. Experimentally confirmed lateral resolution of 2.19 µm was sufficient for the precise non-invasive visualization of abnormalities of fruit specimens. Thus, the proposed variable DOF-OCM system can be an alternative for precisely focused, high-resolution, and variable DOF imaging by improving the DOF in minimum lateral resolution variation.