The measurement of cell stiffness is of great significance in many fields such as biology, medicine and materials science. In order to understand the biomechanical properties and functions of cells, this review first discusses the important application fields of measuring cell stiffness, including tissue engineering, cartilage disease diagnosis, cancer diagnosis and drug development. Secondly, five major measurement techniques are introduced in detail: micro-pillar array method, optical tweezers method, magnetic tweezers method, atomic force microscopy measurement method (AFM), biomembrane force probe measurement method, and the potential and challenges of these five technologies in practical applications are prospected. With its nanometer-level spatial resolution and piconewton-level force resolution, AFM has become a powerful and unique tool in the field of cell mechanics measurement. Therefore, this review focuses on the application and importance of AFM technology and its related computational model, the Hertz model of microsphere-cell contact, in this field, and further elaborates on the types and characteristics of various existing AFM instruments, as well as their application performance in cell mechanics measurement