Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants included in the U.S. Environmental Protection Agency list of priority pollutants because of their toxic, mutagenic, and carcinogenic properties. PAHs have become increasingly prevalent in the soil environment as a consequence of anthropogenic activities. The microbial characteristics of soils are increasingly being considered as sensitive indicators of soil health because of the interrelationship among microbial diversity, soil quality, and ecosystem sustainability. The development of effective methods for studying the diversity, distribution, and behavior of microorganisms in soil habitats is essential for a broader understanding of soil health. Traditionally, the analysis of soil microbial communities has relied on culturing techniques that use a variety of culture media to maximize the recovery of diverse microbial populations. However, only a small fraction (<10%) of the soil microbial community has been accessible using this approach. To overcome these problems, other methods, such as the analysis of phospholipid fatty acids (PLFAs), have been utilized in an attempt to access a greater proportion of the soil microbial community. PLFAs are potentially useful signature molecules because of their presence in all living cells. In microorganisms, PLFAs are found exclusively in cell membranes. This finding is important because cell membranes are rapidly degraded and the component PLFAs are rapidly metabolized following cell death. Consequently, PLFAs can serve as important indicators of active, as opposed to non-living, microbe. Microbial species and biomass in saline-alkali soil contaminated with PAHs were investigated by PLFA analysis, in order to explore the effect of PAHs on the microbial community in saline-alkali soil contaminated with PAHs. The results showed that the distribution of PLFAs in soil can be divided into 4 types (I, II, III, and IV). In Type Ⅰ, the number of microbial PLFAs types in sample soils accounts for up to 57.7% of the total number of microbial PLFAs types, and PAHs in this case are least able to explain the changes of microbial community. In Type Ⅱ, the number of microbial PLFAs types in sample soils is up to 30.8%, and PAHs again provide little explanation regarding the changes of microbial community. In Type Ⅲ, the number of microbial PLFAs types in sample soils comprises up to 7.68%, and PAHs have an increasing effect on the changes of microbial community. In Type Ⅳ, the number of microbial PLFAs types in sample soils comprises only 3.85%, and PAHs have a marked influence on the changes of microbial community. Correlation analysis (Spearman) indicated that the types number, concentration, and diversity index of PLFAs are negatively correlated with the relative content of naphthalene, fluorene, anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and indeno[1,2,3-cd]pyrene, and are positively correlated with acenaphthene, phenanthrene, fluoranthene, pyrene, and benzo[a]anthracene. These results provide a scientific foundation for ecological risk assessment and bioremediation technology of saline-alkali soil contaminated with PAHs.