This study investigates the discharge behavior of a needle-to-plane electrode configuration in water under the influence of repetitive low-energy pulses. An experimental platform was established incorporating high-speed imaging, voltage-current measurements, and shadowgraph diagnostics. The evolution of streamers was systematically examined under varying pulse numbers and polarities. When a voltage is applied to the needle electrode, density perturbations occur around the needle electrode. The density disturbance leads to the decrease of the insulation strength of the liquid, resulting in the emergence of streamers. The discharge in liquid includes corona discharge and breakdown discharge, both of which have polarity effect and have different forms and development speed under different pulses. These findings provide insights into the physical processes of pulsed discharge in water, with implications for underwater plasma applications such as water treatment and plasma chemistry.