Identification and analysis of five different types of white blood cells (WBCs) have a very important application in many fields, such as clinical medicine and life science. In recent years, the digital phase microscopy techniques of red blood cells are remarkably expanded in their observing application. However, due to special optical phase structures of WBCs, the techniques of phase microscopy have difficulty in studying them. Based on this, the analysis of optical characteristics of five types of WBCs is done, and optical models of them are built in this paper. Distribution characteristics of WBCs under these phase models are obtained with numerical simulation techniques. It is found that phase distribution of WBCs is not only related to interference, but also to the scattering of nucleus by analyzing the relationship between phase distributions and classifications of them, but it has certainty to some extent.