The search for concealed hydrocarbon reservoirs in the slope belt of gentle structure seems to be the key to oil and gas exploration in recent years. Due to high concealment, it is very difficult to detect and appraise these reservoirs. Exemplified by the exploration of the concealed hydrocarbon reservoir in Gubei area of the Shengli Oilfield and probing into the key thoughts and the effective methods for detecting the formation conditions and the recognition technology, the authors eventually achieved good effects in the actual application. The research result can play a leading role in the exploration work of similar areas.