Objective To construct and apply the augmentative and alternative communication for mechanically ventilated patients in the ICU, so as to improve nurse and patient communication efficiency. Methods A total of 26 mechanically ventilated patients admitted to cardiothoracic surgery ICU from March to June 2021 were regarded as a control group, who communicated with nurses using a conventional method; and 29 patients admitted from July to October 2021 were taken as an intervention group, who communicated utilizing the augmentative and alternative communication, which included formulating the four elements of the augmen-tative and alternative communication for ICU context, developing communication App and applying in mechanically ventilated patients. The Ease of Communication Scale (ECS), the Hospital Anxiety and Depression Scale (HADS) and a self-designed satisfaction questionnaire were used to investigate the two groups after they were sober-minded (before the intervention) and after removing the ventilator (after the intervention), and the degree of the technology acceptance of the intervention group was surveyed. Results After the intervention,the total score of ECS and HADS of the intervention group were significantly lower than those of the control group, while its satisfaction score was significantly higher (P<0.05 for all), and the score of communication App technology acceptance in the intervention group was (5.54±0.94) points. Conclusion Application of the augmentative and alternative communication system based on communication App can improve the communication efficiency of ICU mechanically ventilated patients, reduce their negative emotion and optimize hospitalization experience.