Objective To compare the difference between modified peroral endoscopic myotomy (Liu?POEM) and conventional POEM for achalasia. Methods Thirty achalasia patients treated with Liu?POEM and 30 with conventional POEM were enrolled. A retrospective study was performed to compare the conventional POEM and Liu?POEM procedures by evaluating total operation time, postoperative complications and symptoms( Eckardt score) . Results The average total operation time of Liu?POEM was 27?13 ±11?42 min and the average myotomy time was 13?20±5?09 min. There was no pneumomediastinum, subcutaneous emphysema or fever. The average total operation time of conventional POEM was 51?22 ± 25?63 min. The average myotomy time was 11?18±7?61 min. There were three cases(10%) of subcutaneous emphysema but recovered after two days without any special treatment. One patient who underwent conventional POEM had fever( the highest temperature was 37?6℃) and his temperature subsided to normal after physical cooling in one day. Postoperative Eckardt scores of patients were all less than 3. After postoperative follow?up of 3 to 12 months, no complications occurred in any patient. Conclusion Liu?POEM is a modified approach to treat achalasia, advantageous over conventional POEM in more simplified operation procedure, shorter operation time and less invasiveness.