Objective To investigate the clinical value of color Doppler ultrasonography in the evaluation of dysfunction ED in patients with diabetes mellitus. Methods 50 patients with type 2 diabetes mellitus complicated with ED in our hospital from January 2011 to December 2013 were selected as observation group, 50 patients with type 2 diabetes without ED were chosen as control group. The general information, ultrasonic testing indicators and the effect of ultrasound on the diagnosis of ED between groups were observed and compared. Results The duration of the observation group was longer than that of the control group, FPG and HbAlc were higher than the control group, the difference was statistically significant (P<0.05). There were no significant difference between the two groups in age and BMI (P>0.05). The PSV, EDV, D and RI of observation group were significantly lower than the control group, the difference was statistically significant (P>0.05). Gold standard for clinical diagnosis, The sensitivity of ultrasound diagnosis and diagnosis was 88.0%, the specificity was 92.0%, the misdiagnosis rate was 8.0%, the missed diagnosis rate was 12.0%, the diagnostic accordance rate was 90.0%. Conclusion Color Doppler ultrasound can directly and quickly get the inner diameter and hemodynamic changes of the penile deep artery in patients with diabetes mellitus, it’s helpful to provide scientific basis for early clinical intervention of diabetic ED.