Objective To explore the evaluation value of two-dimensional speckle tracking technology (2D-ST1) and three-dimensional echocardiography (RT-3DE) for left atrial function in patients with diabetes (DM). Methods 59 patients with DM were selected as the observation group, and 48 healthy subjects were selected as the control group during the same period. The conventional echocardiographic parameters 2D- ST1 parameters and RT-3DE parameters of the two groups were collected and compared. Results The left ventricular end diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) of the observation group were lower than those of the control group (P<0.05). There was no significant difference in the early mitral valve diastolic blood flow velocity (mitral, E), late diastolic blood flow velocity (mitral, A) and peak tricuspid regurgitation velocity (TRPV) between the two groups (P>0.05). The minimum left atrial volume (LAVmin), the maximum left atrium volume of the observation group (LAVmax) and left atrial pre-systolic volume (LAVpre) of the observation group were higher than those of the control group. Meanwhile, the active ejection fraction (LAAEF), total ejection fraction (LATEF), and passive ejection fraction (LAPEF) of the observation group were lower than those of the control group (P<0.05) . The observation group's myocardial strain rate (SR), left ventricular peak strain rate (SRs) during left ventricular systole, left ventricular peak strain rate (SRe) during early diastole, and left atrial peak strain rate (SRa) during atrial systole were lower than those of the control group (P<0.05). Conclusion Compared with conventional echocardiography, both 2D-STI and RT-3DE can detect the changes of left atrial function and myocardial structure in DM patients earlier. However, 2D-STI can more accurately detect the changes in the function of the left atrium channel, reservoir and booster pump, and 3D-STI can accurately track the movement and deformation of the left atrium endocardium in three-dimensional space.