Chemotaxis is the response ability of motile cells to chemicals gradients in environment and the migration toward higher concentration of chemoattractant or lower concentration of repellent. This mechanism is a basic nature of microorganisms to adapt to the environmental changes. The research of microbial chemotaxis is of great significance in utilizing bacteria to solve environment problems, control the pathogen infection, and develop microbial industrial projects. Microfluidic devices can realize qualitatively and quantitatively detect of bacterial chemotaxis. In comparison with traditional detect methods, microfluidic assay has an accurate control over bacterial microenvironment, with a higher sensitivity. In the past few years, bacterial chemotaxis study based on microfluidic assay was developed rapidly. In this paper, the microfluidic chemotaxis detectors that appeared in recent years were introduced from the aspect of chip structure, working principle and their applications. Finally, we provided insights into the challenges of bacterial chemotaxis and provided future perspectives.