Objective To observe the influence of cognitive behavioral therapy（ CBT） combined with drugs on performing function in adult patients with attention deficit hyperactivity disorder（ ADHD）. Methods A total of 105 cases of adult patients with ADHD from the Psychology Outpatients Clinic of Armed Police Hospital of Guangdong Province and Guangdong 999 Brain Hospital were selected. According to different treatment regimens， they were divided into combined group， drug group and CBT group， with 35 cases in each group. The drug group was treated with conventional drugs. The CBT group was given CBT. The combined group was given CBT on the basis of drug treatment. The clinical treatment effect and performing function of the three groups were assessed with ADHD scale and Behavior Rating Inventory of Executive Function-Adult （BRIEF-A）. Results The scores of ADHD and BRIEF-A in the three groups after treatment were significantly lower than those before treatment（ P＜0.05）. The score of the combined group was lower than that of the durg group and CBT group（ P＜0.05）. There was no statistical difference between the drug group and CBT group after treatment（ P＞0.05）. Conclusions The cognitive behavioral therapy combined with drug is helpful to improve the performing function such as self monitoring， inhibition， emotional control and so on in adult patients with attention deficit hyperactivity disorder and increase the clinical therapeutic effect.