Objective To research a method to reduce the dosage of contrast in the process of percutaneous coronary intervention. Methods Thirty one patients with at least one lesion were divided into routine technique group (12 patients,RT group),magnetic navigation system(MNS) assistant group (11 patients,MA group) and multiple technique group (11 patients,MT group). Parameters including procedure time,X ray exposure time,dosage of contrast were recorded in all cases. Results Among three groups (RT,MA and MT group),there were no significant differences in gender and lesion location.. The time of procedure had significant difference among RT,MA and MT groups,(42.2±18.1),(58.7±23.5),(71.9±28.4)min respectively,MT group needed the longest time. The dosage of contrast had significant difference among the 3 groups,(76.5±12.6),(43.4±9.7),(36.3±6.2)ml respectively,RT group used the highest dose of contrast. X ray exposure time,the incidence of major adverse cardiac events and the residual stenosis ratio had no significant difference among the 3 groups.Conclusion The dosage of contrast can be reduced markedly in the procedure assisted with MNS and optical coherence tomography. Though the procedure time was prolonged in MT group,X ray exposure time had no difference among 3 groups.