The newly proposed image sensor based optical receiver has become a ke y technology and research hotspot with its advantages of high signal-to-noise ratio (SNR),high receiving bandwidth and spatial division multiplex (SDM) characteristics,over the conditional optical receivers like pho todiode (PD),photon multiplication tube (PMT) and photodiode array based receiver.This paper firstly studies the c haracteristics,including the optical and electrical characteristics,of the image sensor based optical receiver based on t he analysis results of the image sensor′s working model.Image sensor device noises,including the fixed pattern noise (FPN ) and temporal noise like pixel noise,read noise,analog to digital convertor (ADC) noise,are also carefully st udied.An optimized receiving algorithm for the image sensor based receiver is also proposed based on the bit error rate (BER) variation characteristics of visible light communication (VLC) system,with respect to the image sensor′s exposure time and decision threshold,which is closely related to the number of the incident photo ns and the excited electrons. Simulation results show that the proposed algorithm can generate the optimized exposure time and decision threshold based on the system parameters like emitting light angle,incident lig ht angle,signal propagation distance and data rate,and it can improve the VLC system′s anti-interference capability and achieve its best BER performance,effectively.