Objective To analyze the difference of cognitive impairment between bipolar disorder Ⅰ and Ⅱ patients in remission stage. Methods The patients in the outpatient and inpatient department of Beijing Huilongguan Hospital from January to December 2020 were selected as the research subjects. According to the diagnostic criteria of DSM-5， the patients were assigned into Bipolar disorder Ⅰ and Ⅱ group， with 30 cases in each group. At the same time， 35 healthy controls matched for gender， age， education background were recruited. The general situation questionnaire， Young's Mania Scale， Hamilton Depression Scale and MATRICS Consensus Cognitive Battery （MCCB） test were applied in the investigation. Spearman correlation was used to analyze the correlation between cognitive function and clinical data in patients with bipolar disorder. Results Comparing among the 3 groups， the differences in verbal learning ［（51.07±9.75） vs （57.07±9.67） vs （57.66±6.96）］， visual learning ［（46.17±12.03） vs （53.80±6.39） vs （55.57±7.47）］， reasoning problem solving ［（49.80±10.24） vs （55.03±5.44） vs （55.80±7.33）］and total MCCB scores ［（48.33±8.55） vs （53.10±6.97） vs （55.86±5.11）］were statistically significant （F=5.333， 9.885， 5.336， 9.636； P ＜ 0.05）. Comparing between bipolar disorder group and control group， the differences in processing speed ［（52.00±8.94） vs （60.74±7.50）］， speech learning ［（54.07±10.09） vs （57.66±6.96）］， visual learning ［（49.98±10.30） vs （55.57±7.48）］， reasoning problem solving ability ［（52.42±8.55） vs （55.80±7.33）］and total MCCB scores ［（50.72±8.10） vs （55.86±5.11）］ were statistically significant （t=4.871， 1.861， 2.806， 2.040， 3.379； P ＜ 0.05）. Spearman correlation analysis showed that the number of episodes of hypomania was positively correlated with visual learning and memory， the number of episodes of mania and reasoning was negatively correlated with problem solving ability， and the number of episodes was negatively correlated with attention/vigilance （P ＜ 0.05）. Conclusions Cognitive impairment was greater in patients with bipolar Ⅰ than in patients with bipolar Ⅱ， and the cognitive impairment remained in patients with bipolar who in remission stage.