There were more complicated problems in the oil test of LX-1 well, which greatly hampered the whole construction process of the well. Based on the previous knowledge of oil test construction, this study examined the difficulties of oil test technology in the Wujiaping formation, and considered that the high pressure and low permeability of the Wujiaping formation, complex well structure, insufficient performance of pressure fluid, and small borehole size were the main factors affecting the oil test construction in this formation, and made corresponding suggestions and recommendations. The study demonstrated that: (1) the Wujiaping formation was characterized by poor physical properties and high pressure, and the reasonable configuration of acid fracturing can connect the reservoir more effectively, but the pressure level of well control equipment must be well considered; (2) due to the high density of non-solid phase fracturing fluid, there was a risk of crystalline precipitation and wellbore clogging at high temperature and pressure; (3) Downhole salvage tools and tool combinations should be optimized for ultra-deep wells with small borehole operations, and the selection should take into account the problems of high temperature and high pressure in the formation, small gap in the annulus, downhole plugging and downhole tool failure, so as to make a good retreat and avoid creating new complex problems. After the field application, LX-1 ultra-deep small well was safely and smoothly salvaged, which accumulated experience for similar oil test operation in the future, and has good guiding significance for similar wells to improve the exploitation yield, reduce the complexity of wells, shorten the work cycle and save the development cost.