With the development of Real-time Service (RTS) project, timing users can apply the real-time Precise Point Positioning (PPP) technique for time transfer. As a participant in the RTS project, Centre National d'Etudes Spatiales (CNES) implements the PPPWIZARD (Precise point positioning with Integer and Zero-difference Ambiguity Resolution Demonstrator) project to validate the PPP ambiguity resolution. In order to analyze the contribution of multiple global navigation satellite system (multi-GNSS) and real-time ambiguity resolution to time transfer, our experiment used the observation from multi-GNSS, including GPS (Global Positioning System), GLONASS (GLObal NAvigation Satellite System), BDS (BeiDou navigation System), and Galileo for data processing. Meanwhile, the real-time products from CNES were utilized to examine the performance of four different PPP processing modes. The experimental results indicated that, of all the processing modes, time transfer using multi-GNSS PPP with GPS ambiguity resolution had the smallest standard deviations (STDs). The STD value was decreased by 38.1%, compared with the time transfer results using GPS PPP.