Dead-end hydrogen-oxygen PEM fuel cell has been limited by easily flooding. To figure out how water transport in channels affects performance of fuel cells, a transparent fuel cell with its both sides visualized is assembled and works under different workloads, of which effect on water transport and performance is studied. Meanwhile, a visualized fuel cell with water transport plate in cathode is proposed to study its impact on the performance and water transport of fuel cells. It is found by experiment that performance degradation is mainly caused by cathode flood which is most likely to occur at 0.5A/cm² when the maximum cathode WCR is only 35%. Maximum anode WCR increases with the rise of current density since the back diffusion enhances; and anode flood with WCR reaching 45% at 0.8A/cm² causes voltage drop. Water transport plate provides excellent drainage ability for fuel cell. Thus transparent fuel cell with water transport plate has stable performance. Maximum anode WCR of cell with water transport plate is no more than 23% and decreases when current density increases as a result of stronger electro-osmatic drag and reactive gas purge.