Objective To observe the effects of selecting different cognitive tasks during dual-task stepping training assisted by a pelvic weight support rehabilitation robot on cerebral cortex activation and task performance in convalescent period stroke patients. Methods Convalescent period stroke patients treated at Huashan Hospital, Fudan University between June 2023 and July 2024 were selected. Patients were recruited and conducted a self-controlled study. Patients were subjected to a self controlled study and received AB regimen training. The plan A underwent dual-task verbal fluency-stepping training assisted by the pelvic weight support rehabilitation robot, while the plan B performed dual-task serial subtraction-stepping training assisted by the pelvic weight support rehabilitation robot. During the intervention process, near-infrared equipment was used to collect relative oxyhemoglobin (HbO2) concentrations in six brain areas including prefrontal cortex (PFC), supplementary motor area (SMA), and primary motor cortex (PMC). The correct response rate and average number of steps were collected. Results A total of 20 patients were included. Among them, there were 16 males and 4 females. The average number of steps in Plan A were higher than those in Plan B (P<0.05). The correct response rate and the relative increase in HbO2 concentration of PFC, PMC, and SMA in both hemispheres of Plan A was higher than that in Plan B, but there was no statistically significant difference between the groups (P>0.05). Conclusions Compared with the dual-task serial subtraction-stepping training assisted by the pelvic weight support rehabilitation robot, the dual-task verbal fluency-stepping training assisted by the pelvic weight support rehabilitation robot can significantly increase the mean number of steps in the dual tasks.