Feature extraction and phase retrieval, as critical technical nodes in imaging technologies, play a pivotal role in label-free biological imaging and target recognition. Optical differential imaging is pivotal for extracting phase information in label-free biological imaging and feature extraction, yet existing techniques often suffer from complexity, limited adjustability, and anisotropic signals. Here, we propose an adjustable weak measurement differential microscopy that integrates a flat differentiator with weak measurement to achieve flexible, high-precision phase imaging. By modulating the orientation and incident angle of a uniaxial crystal, we demonstrate tunable spatial differentiation in both strength and direction, enabling isotropic edge detection and phase mining. Furthermore, the system enables rapid switching between optical spatial differentiation and differential interference contrast imaging modes via post-selection state adjustments to accommodate different application scenarios. The results demonstrate this miniaturized, modular approach enables breakthrough capabilities in automated sensing, label-free microscopy, and optical computing systems.