The development of the digital economy in China is in the ascendant, and the development of new business models and industrial patterns under the digital economy has promoted the upward trend of the economy and the growth of labor income, as well as brought about the vigorous development of informal employment forms. The expansion of the informal employment market has absorbed a large amount of rural labor, providing new exports for the employment of migrant workers. The development of the digital economy also affects the wage income at the individual level. However, current research is mostly based on formal employment. Informal employment groups, as vulnerable groups in the digital economy, have received little attention. This article uses data from the 2018 and 2020 China Statistical Yearbook and Chinese Family Panel Studies. Firstly, a multi-layer model of the wage equation for migrant workers is established, and the differences in the impact of the digital economy on the income of migrant workers are explored from the perspectives of formal and informal employment, as well as the moderating role of individual abilities in it. Secondly, use Oaxaca Blinder decomposition to clarify the sources of wage differences between the two types of migrant workers, and further explore the impact and path of the digital economy on their wage differences. Research has found that the higher the level of development of the digital economy, the higher the salary income of migrant workers, and the income increasing effect of the digital economy is higher for formal employment migrant workers than for informal employment groups. Among them, individual abilities have a positive regulatory effect on the wage growth brought about by the digital economy. The Oaxaca-Blinder decomposition results show that the wage gap between the two types of migrant workers comes from the development of the digital economy and individual ability differences. The digital economy expands the wage gap in terms of characteristic differences and reward differences. Furthermore, the development of the digital economy expands the wage income gap between formal and informal migrant workers, and expands the wage income gap between the two types of migrant workers by promoting the regularization of employment for highly non-cognitive migrant workers. Compared to previous literature, this article mainly expands on the following three aspects: firstly, it focuses on individual workers in the context of the digital economy, and focuses on migrant workers as the main research object; secondly, it focuses on the informal employment group to analyze the impact of the digital economy on the wage gap between formal and informal migrant workers; thirdly, it explores the intrinsic mechanism of digital economy development affecting the wage income of the two types of migrant workers, and analyzes the moderating role of cognitive ability and non-cognitive ability in it, and also explores the intrinsic mechanism of digital economy development affecting the wage income difference between the two types of migrant workers, and analyzes the mediating role of cognitive ability difference and non-cognitive ability difference in it. This study reveals the bias of the income increase effect of digital economy development in the formal and informal employment of migrant workers, explores the internal logic of the impact of digital economy development on the wage gap between formal and informal employment of migrant workers, and provides references for Chinese government departments to formulate better employment guidance measures for migrant workers, in order to provide differentiated policy support for migrant workers of different job types.