The timing synchronization system (TSS) plays an important role in the experiments of the Experimental Advanced Superconducting Tokamak (EAST). The purpose of this system is to synchronize each subsystem of EAST according to the reference clock and delay trigger signal, and ensuring stable operation of the EAST fusion device. A prototype TSS module based on precision time protocol (PTP) has been developed using the PXI bus standard and FPGA devices. This new TSS can provide reference clock signals with frequency of up to 50 MHz with isolation fan-out devices. The maximum trigger skewing between different nodes is less than 10 ns. This new TSS is more expandable and suitable for the synchronization and timing control of the EAST fusion experiment. It has been in steady operation since the 2016 EAST experimental campaign. This paper concentrates on the modifications of the TSS, the details about the system architecture and test results will be described in this manuscript.