Objective To investigate the value of bedside diaphragmic ultrasonography combined with transthoracic echocardiography in detecting diaphragmic excursion (DE), mitral valve early diastolic peak flow velocity (E)/mitral annular early diastolic peak velocity (e?), and left ventricular ejection fraction (LVEF) in the weaning patients with invasive mechanical ventilation. Methods Fifty patients who underwent invasive mechanical ventilation in the respiratory intensive care unit of the First Affiliated Hospital of Bengbu Medical University from January 2019 to August 2023 were selected as the study subjects, and they were divided into the successful weaning group and the failed weaning group according to the outcome of the weaning, and the general data and DE, E/e?, and LVEF levels of the patients in the two groups were collected and evaluated to assess the joint prediction of invasive by the levels of DE, E/e?, and LVEF in the value of weaning outcome in mechanically ventilated patients. Results The DE and LVEF levels of patients in the successful weaning group before weaning of invasive mechanical ventilation were (1.17±0.26) cm and (56.84±7.02)%, respectively, which were higher than those of patients in the unsuccessful weaning group (0.86±0.17) cm and (46.33±6.86)%, and the differences were statistically significant (P ＜ 0.05), whereas the E/e? levels of patients in the successful weaning group (9.64± 1.08) were lower than those of patients in the failed machine weaning group (10.67±1.17), and the difference was statistically significant (P ＜ 0.05). The results of ROC curve analysis showed that the AUCs of DE, E/e?, LVEF, and their combined test for predicting the outcome of weaning patients with invasive mechanical ventilation were 0.827, 0.721, and 0.763, respectively, and the AUC for the combination of the three for predicting the outcome of weaning in patients with invasive mechanical ventilation was 0.935. Conclusions Bedside diaphragmic ultrasonography combined with transthoracic echocardiography in invasive mechanically ventilated patients to detect the levels of DE, E/e?, and LVEF can predict patients’ weaning outcome, which helps to further improve the accuracy of predicting ventilator weaning outcome.