Objective To observe the effect of aggressive lipid-lowering therapy with simvastatin on the lipoprotein (a)(LP(a)) level and the risk of in-stent restenosis(ISR)in coronary heart disease(CHD)patients after coronary stent implantation. Methods From January 2016 to June 2017, 100 CHD patients with coronary stent implantation in our department of Cardiology were taken as the research objects, and they were randomly divided into strengthened group (50 cases) and control group (50 cases). The control group was treated with oral simvastatin 20mg/d, while the strengthened was treated with oral simvastatin 40mg/d. Six months after treatment, the effects of the two groups were observed and compared. Results Six months after treatment, the TC, TG, LDL-C and LP (a) levels in the two groups were significantly lower than those before treatment (P<0.05), and the improvements of TC, TG, LDL-C and LP (a) in the strengthened group were better than those in the control group (P<0.05); the LVEF levels in the two group were significantly higher than those before operation (P<0.05), the LVEDD levels in the two groups were significantly lower than those before operation (P<0.05), and the improvements of LVEF and LVEDD in the strengthened group were better than those in the control group (P<0.05); the incidence rate of ISR in the strengthened group was 6.00% which was significantly lower than that in the control group 22.00% (P<0.05). Conclusion Aggressive lipid-lowering therapy with simvastatin, which has no obvious adverse reactions, can reduce the levels of serum lipid and LP (a), improve the cardiac function of patients and reduce the incidence rate of ISR for CHD patients after coronary stent implantation.