Objective Through a retrospective study on esophageal function changes and symptom relief after video-assisted thoracoscopic surgery treatment for achalasia of cardia (AC) to assess the clinical value of this operation. Methods We reviewed the data of 34 AC patients who received modified Heller operation by video-assisted thoracoscopic surgery in the Affiliated Hospital of Guizhou Medical University from March 2012 to September 2014. There were 11 males and 23 females with a median age of 35 (11–67) years. These patients were divided into four groups according to the time of treatment and follow-up: preoperative group, postoperative one-month group, postoperative three-month group and postoperative six-month group. Changes of symptoms, radiography and esophageal dynamics before and after therapy were collected. These different groups were analyzed based on statistical methods. Results There was no statistical difference in ages and genders among groups (P>0.05). The surgery was successful and no complication or death occurred. Symptoms of patients showed different degrees of relief and the postoperative grade of clinical symptoms decreased (P<0.05). After surgery, lower esophageal sphincter pressure (LESP), lower esophageal sphincter resting pressure (LESRP) and esophageal body pressure (EBP) decreased significantly, while lower esophageal sphincter relax rate (LESRR) increased (P<0.05). While there was no significant difference in length of lower esophageal sphincter (LESL,P>0.05). Angiography of upper digestive tract revealed that compared to the preoperative group, the maximum width in postoperative three-month group decreased significantly (P<0.05). During the follow-up, 3 patients suffered gastroesophageal reflux, 2 patients esophageal perforation and 1 patient empyema due to esophago-pleural fistula. No massive hemorrhage of upper digestive tract and hiatal hernia occured. Conclusion Sugery can significantly ameliorate the clinical symptoms of the patients with AC, and improve esophageal dynamics. And it is simple and easy to perform with less complications and better long-term outcomes. Improved Heller operation by video-assisted thoracoscopy is a less invasive procedure when compared with the traditional thoracotomy. Moreover, esophageal manometry can objectively assist in the diagnosis and degree of the disease and effect of therapy.