Previous studies have shown that formaldehyde (FA) could cause immunotoxicity by changing the number of T lymphocytes and that cytokines play a pivotal role in the regulation of T lymphocytes. However, the previously used cytokine detection methods are difficult to use in the measurement of several cytokines in a small amount of sample for one test. Therefore, the cytometric bead array (CBA) technique was used. CBA showed better analytical efficiency and sensitivity than the previous methods. C57BL/6 mice were exposed to the control (normal saline), low FA concentration (0.5 mg/kg), and high FA concentration (2 mg/kg) for 1 week or 1 month. The contents of cytokines, including Th1-related cytokines (IL-2, IFN-γ, and tumor necrosis factor), Th2-related cytokines (IL-4, IL-6, and IL-10), and Th17-related cytokines (IL-17A), were measured by using the BD FACS Canto II Flow Cytometer and analyzed by FCAP ArrayTM Software. Th1/Th2/Th17-related cytokines showed a slightly decreasing trend after low FA exposure. Conversely, a significantly increasing trend was found after high FA exposure. Th1/Th2/Th17-related cytokines all serve important functions in the immune reactions in mice after FA exposure.