Phase diversity technology can directly use the intensity information of two or more images to reconstruct the wavefront information and high-resolution image of the target. It has the advantages of simple optical setup, low cost and suitable for extended targets. It has been widely used in system aberration detection and target image reconstruction of telescopes. The key point of phase diversity wavefront sensing is to solve the optimization problem of nonlinear cost function. It needs to avoid falling into local extremum and reduce the calculation time to meet the demand of real-time sensing of dynamic wavefronts. Meanwhile, regularization and denoising are usually needed to improve the quality of reconstructed image. This paper mainly introduces the basic principle of phase diversity technology, as well as the research progresses in recent years, and prospects for future development of this technology.