ABSTRACTBackgroundTumor budding is an independent predictor of metastasis and prognosis in colorectal cancer and is a vital part of the pathology specification report. In a conventional pathological section observation process, pathologists have to repeatedly switch from 10× objective to 20× objective several times to localize and image the target region. Besides the switching operations, repeated manual or electro‐mechanical focusing is also very time‐consuming, affecting the total time for pathological diagnosis. In addition, it is usually necessary to remove the manually marked symbols on the stained pathology slides used for classification and management before observation.MethodsIn this paper, we utilize Fourier ptychographic microscopy (FPM) in the pathological diagnosis process to realize large space‐bandwidth product imaging, quantitative phase imaging, and digital refocusing in the observation process without any mechanical operations, which can therefore simplify the above‐mentioned cumbersome diagnostic processes. We first verify the effectiveness and efficiency of the proposed method with several typical pathological sections. Then, instead of manually erasing, we also prove that the FP framework can digitally remove the artificial markers with its digital refocusing ability.ResultsAt last, we demonstrated pathologists can achieve 100% diagnostic accuracy with FPM imaging results.ConclusionsThe proposed method can greatly simplify the process of pathological diagnosis, and the related addon hardware system does not require expensive components, which gives it great potential for promotion in the field of pathological diagnosis.