Objective: To analyze the impact of dual antiplatelet (DAPT) therapy combining with or without proton pump inhibitors (PPI) on the main outcomes after percutaneous coronary intervention (PCI). Methods: The PubMed, EMBASE and Cochrane Library were searched for relevant literature and the references obtained from these sources were retrieved manually from inception till September 2017. Inclusion and exclusion criteria were established follow the Cochrane review standard. A total of 977 literatures were included, 193 duplicates were excluded, 74 reviews, case reports, letters and systematic reviews were excluded, 667 literatures were excluded after reading the title and abstract, 34 literatures were excluded due to non-randomized control studies and unrelated outcome indicators, and 9 literatures were finally included with a total of 16 589 patients. RevMan 5.3 software was used to compare the incidence of major adverse cardiovascular events (MACE), cardiogenic death, recurrent myocardial infarction, target vessel revascularization, all-cause death, stent thrombosis, stroke, gastrointestinal bleeding and gastrointestinal events in patients with DAPT combining with or without PPI after PCI. Results: MACE was observed in 8 out of the 9 included literatures, and the results showed that MACE occurred in 561 out of 6 282 patients receiving DAPT combining with PPI therapy and in 951 out of 9 632 patients using DAPT alone (OR=1.15, 95%CI 0.88-1.51, P>0.05). Cardiogenic death was observed in 7 out of the 9 included literatures, and the results showed that cardiogenic death occurred in 172 out of 6 453 patients receiving DAPT combining with PPI treatment and in 321 out of the 9 839 patients using DAPT alone (OR=0.97, 95%CI 0.80-1.18, P>0.05). Recurrent myocardial infarction was observed in 7 out of the 9 included literatures, the results showed 416 out of 6 282 cases in DAPT combining with PPI therapy group experienced recurrent myocardial infarction and 691 out of 9 632 cases in DAPT group experienced recurrent myocardial infarction (OR=1.01, 95%CI 0.89-1.16, P>0.05). Four out of 9 literatures observed revascularization. The results showed that revascularization was performed in 64 out of 2 173 patients receiving DAPT combining with PPI therapy and in 105 out of the 2 770 patients using DAPT alone (OR=1.33, 95%CI 0.55-3.24, P>0.05). All-cause death was observed in 7 out of the 9 included literatures, and the results showed that all-cause death occurred in 172 out of the 6 453 patients in DAPT combining with PPI therapy group and in 321 out of the 9 839 patients using DAPT alone (OR=0.97, 95%CI 0.80-1.18, P>0.05). Three out of the 9 included articles observed stent thrombosis, and the results showed that stent thrombosis occurred in 99 out of 2 997 patients receiving DAPT combining with PPI therapy and in 245 out of the 6 198 patients treated with DAPT (OR=1.07, 95%CI 0.83-1.37, P>0.05). Stroke was observed in 2 out of the 9 included literatures. The results showed that stroke occurred in 5 out of 2 019 patients receiving DAPT combining with PPI therapy, and in 4 out of the 2 033 patients treated with DAPT (OR=1.00, 95%CI 0.29-3.49, P>0.05). Gastrointestinal bleeding was observed in 6 out of the 9 included literatures. The results showed that gastrointestinal bleeding occurred in 26 out of 3 517 patients receiving DAPT combined with PPI therapy, and in 93 out of the 3 506 patients treated with DAPT, gastrointestinal bleeding was significantly lower in the DAPT combining with PPI group than DAPT alone group (OR=0.27, 95%CI 0.17-0.41, P<0.01). Gastrointestinal events were reported in 6 out of the 9 included articles. Similarly, gastrointestinal events were observed in 51 out of 3 517 patients receiving DAPT combined with PPI therapy, and in 190 out of the 3 506 patients treated with DAPT alone, the incidence of gastrointestinal events in the DAPT combined with PPI group was significantly lower than DAPT alone group (OR=0.24, 95%CI 0.14-0.42, P<0.01). Conclusions: The incidence of MACE, cardiogenic death, recurrent myocardial infarction, target vessel revascularization, all-cause death, stent thrombosis and stroke are not affected by DAPT combined with PPI therapy after PCI, while the incidence of gastrointestinal bleeding and gastrointestinal events could be reduced by adding PPI to DAPT in patients undergoing PCI.