Underwater Wireless Optical Communications (UWOC) is an emerging high-speed underwater communication technology that has gradually attracted widespread attention in academia and industry due to its advantages of high transmission bandwidth, electromagnetic interference resistance, low power consumption, and small size. Although light has a larger attenuation in underwater transmission than acoustic wave, its transmission distance can still reach hundreds of meters, which is sufficient to meet the requirements for sensor data transmission. However, UWOC technology is still in an early stage of development, with most experiments being conducted only in laboratory water tanks. Therefore, unified performance testing models and methodologies are required due to different testing methods for UWOC. In order to objectively evaluate the performance of a UWOC system, this article attempts to propose the general testing method, model and evaluation indicators for UWOC systems, to promote the development of UWOC technology.