With the increasing demand of access network bandwidth,100 Gb/s/λ coherent passive optical network (PON) has become the key of future PON.In this paper,a 100 Gb/s/λ homodyne coherent dual polarization-16 quadrature amplitude modulation (DP-16QAM) PON system based on blind phase search (BPS) algorithm is proposed.The system uses pulse-shaped polarization division multiplexing (PDM)16QAM signals on the optical line terminal (OLT) side to reduce the symbol rate.On the side of optical network unit (ONU),homodyne coherent detection technology is used to receive signals,and the BPS algorithm is used to process the system phase noise during the digital signal processing (DSP) process.The simulation results show that the system can achieve a power budget of 32.2 dB after 20 km standard single mode fiber (SSMF) transmission.At the same time,by using the BPS algorithm with a high linewidth tolerance,when the bit error rate (BER) is 10-4,after 20 km of fiber transmission,the sensitivity loss of the 10 MHz laser line width is only 0.6 dB more than that of 0.1 MHz,which allows the large linewidth laser to be used on the OLT side of the coherent PON system to reduce system costs.