Cell observations and analysis are often required in biological and medical fields for cell condition evaluations and disease diagnostics. Compared to classical methods such as bright/dark field microscopy and fluorescent microscopy, quantitative interferometric microscopy as one of the quantitative phase microscopic techniques is able to provide high contrast image of label free samples thus can be potentially using in live cell imaging. While it often suffers from the low processing speed often due to the heavy computational load in phase unwrapping. In order to accelerate the imaging speed, we design a rapid cell phase imaging technique relying on the fast shearing phase unwrapping method. It can extract the sample information from a single-shot interferogram showing that it can capture live cell images. Moreover, the phase unwrapping process is significantly reduced with accelerated speed. Considering the system can provide quantitative and high-contrast live cell imaging in label free mode with high accuracy, fast speed and large field of view, it can be a potential tool for cell observations and measurements in biological and medical applications.