Monitoring the bridge structural health and finding bridge damages in time are of great significance to ensure the safe operation of bridges. In this paper, we aim to evaluate the availability of Global Navigation Satellite System (GNSS) precise point positioning (PPP) technology in bridge structural health monitoring with float ambiguity solution and with inter ambiguity resolution (PPP-IAR). Based on 10 stations evenly distributed in China, we find that PPP-IAR solutions have a faster convergence speed than PPP solutions, and the accuracy of better than 1 cm in horizontal and 2 cm in vertical direction can be achieved by GPS/BDS/Galileo (GCE) combined PPP-IAR. From a simulated displacement experiment, PPP-IAR has a better accuracy and faster convergence speed than PPP for the identification of displacements at different levels. Finally, the fieldwork experiment of three bridges with different spans and states are conducted. Results show that both PPP and PPP-IAR method can effectively identify the bridge vertical displacements resulting of the vehicle loading at centimeter accuracy. Meanwhile, PPP and PPP-IAR method are capable of extracting low-order vibration signals of bridge, which are comparable to the double-difference (DD) solution. It demonstrates that PPP and PPP-IAR technology could be an alternative method to DD for bridge health monitoring, and PPP-IAR is expected to have a faster convergence speed and higher accuracy in the real-time monitoring of bridges.