[Objective] The aim of this study was to screen the reference genes of Agaricus brasiliensis under different experimental conditions, especially under cadmium (Cd) stress, and to lay the foundation for studying the functional studies of cadmium enrichment-related genes in A. brasiliensis.[Methods] We screened 18 candidate genes and designed 30 primer pairs based on the transcriptomes of mycelia under the stress of different concentrations of Cd (0, 2, 5 mg/L). According to the specificity and amplification efficiency of primers, 5 pairs of primers from different genes were selected. The Ct values of mycelia, primordium, stipe, and pileus of 5 genes under different concentrations of cadmium stress were detected by QRT-PCR, and the expression stability of these genes was evaluated by geNorm, NormFinder, and BestKeeper. [Results] The results showed that Small glutamine-rich tetratricopeptide repeat-containing protein 2 (SGT2) and Serine/threonine-protein kinase (STK) were the two most stable candidate reference genes under Cd stress in the mycelial stage, GAPDH was the most stable reference gene in different tissues and SGT2, STK and GAPDH were the three most stable reference genes under all experimental conditions. [Conclusion] Under Cd stress conditions in A. brasiliensis, SGT2 and STK screened in this study were more stable compared to the commonly used reference genes.