在数字信号系统中，由于噪声和码间干扰的存在，信道的特性很不稳定，为了稳定信道的特性，有效地解决噪声和码间干扰存在的问题，让信息能够有效的传输，避免出现漏传现象。因此，设计了眼图观测系统，通过眼图观测系统观测到的特性参数来衡量传输基带系统性能的优劣。根据眼图观测系统设计进行数字信号光纤传输测试，依据测试观测得到关于眼图的特性参数，计算出眼皮的开度、厚度、定时抖动能力等，用此能够评价一个系统性能的优劣。 In the digital signal system, due to the existence of noise and intersymbol interference, the cha-racteristics of the channel are very unstable. In order to stabilize the characteristics of the channel, the problems of noise and intersymbol interference can be effectively solved to enable the infor-mation to be transmitted effectively and avoid the phenomenon of leakage. Therefore, an eye pat-tern observation system is designed to measure the performance of the transmission baseband system through the characteristic parameters observed by the eye pattern observation system. Optical fiber transmission test of digital signal was carried out according to the design of eye pat-tern observation system. The characteristic parameters of eye pattern were obtained according to the test observation, and the opening, thickness and timing jitter ability of eyelid were calculated, which could be used to evaluate the performance of a system.