Abstract The glycolytic enzyme, fructose‐1,6‐bisphosphate aldolase B (ALDOB), is recognized for its key role in shaping tthe umor immune microenvironment. However, the precise ways in which it influences the CD8 + T cell immune response in colorectal cancer (CRC) are still largely unknown. This study is designed to elucidate the interplay between ALDOB and the immune system in CRC. We analyzed the high expression of ALDOB in CRC tissues and cells through bioinformatics, clinical samples and in vitro experiments, finding that it promoted tumor progression. Its high expression was negatively correlated with CD8 expression and positively correlated with PDL1 expression. Further cell experiments revealed that ALDOB overexpression enhanced the expression of WNT signaling pathway‐related proteins (β‐catenin and c‐myc), which in turn promoted PDL1 expression in CRC cells, inhibiting the proliferation and killing effect of CD8 + T cells in co‐culture systems. Our findings disclose how ALDOB influences CD8 + T cell recruitment and antitumor immune function, proposing it as a potential target for the treatment of CRC.