A press fitting mechanism comprises a press fitting assembly, a carrier assembly and a pressing mechanism; the press fitting assembly comprises a pressing head assembly mounted on an alignment adjusting module, the pressing mechanism comprises a pressing lever pressed on a pressure sensor, and the pressure sensor is arranged on the top of the pressing head assembly; through the mechanism, a precise alignment component and a pressure applying component are controlled in a separated manner, alignment precision can be ensured, and it can be ensured that enough pressure is applied; the lever pressurizing manner is adopted, the pressure can be controlled through the pressure sensor, the mechanism can adapt to press fitting of different products, and the press fitting seal effect is good.