Objective To investigate the effect of L-carnitine combined with Shengmai Injection on cardiac function in patients with maintenance hemodialysis hypotension. Methods A total of 120 maintenance hemodialysis patients with recurrent hypotension in our hospital from January 2016 to February 2020 were randomly divided into control group (n=40), L-carnitine group (n=40) and combination group (n=40). The three groups were treated with conventional treatment, L-carnitine group was added with L-carnitine, and the combination group was given levocarnitine combined with Shengmai Injection. The incidence of hypotension, blood pressure index, myocardial enzyme spectrum, quantitative index of myocardial infarction and echocardiography index were obtained and analyzed before and after treatment. The adverse reactions in the three groups were collected. Results The incidence of hypotension in combination group was lower than that in control group and L-carnitine group (P<0.05). After treatment, the minimum systolic blood pressure, mean arterial pressure during dialysis, systolic blood pressure after dialysis and mean arterial pressure after dialysis in the combination group were higher than those in the control group and L-carnitine group (P<0.05). After treatment, the myocardial spectrum enzyme and myocardial infarction quantitative indexes in the combination group were lower than those in the control group and L-carnitine group (P<0.05). There were no significant differences in pulmonary artery systolic pressure, diastolic right ventricular wall thickness, diastolic right ventricular width, diastolic left ventricular width, systolic right ventricular area and diastolic right ventricular area among the three groups before and after treatment (P>0.05). The left ventricular ejection fraction of the combination group was higher than that of the control group and L-carnitine group (P<0.05). There was no significant difference in the incidence of adverse reactions among the three groups (P>0.05). Conclusions L-carnitine combined with Shengmai Injection could reduce the incidence of hypotension in maintenance hemodialysis patients, improve the cardiac function, with good efficacy and safety.