Xi233 area Chang7 reservoir in Ordos Basin is one of the typical shale oil reservoirs in China. In the early stage of production relying on quasi-natural energy，oil production declines fast and oil recovery is low. Given abundant associated gas resources，we selected typical shale oil reservoir rock samples to conduct the gas-flooding experiment and huff-puff experiment in the shale oil samples with the associated gas by the nuclear magnetic resonance technology. The results show that the oil is mainly produced from the medium and large pores，while the recovery percent of micropores is lower，and oil recovery is less than 43% in the associated gas-flooding process. Compared with the saturated oil samples，the samples with irreducible water show the lower oil recovery，which is affected by factors such as pore heterogeneity，specific surface area，and irreducible water. In the huff-puff process with associated gas injection，oil is also mainly produced from the medium and large pores. Compared with the flooding experiment with associated gas injection，the recovery percent in each level of pores is greater in the huff-puff oil recovery process，and the oil recovery of samples is greater than 44%. With the increase in the huff-puff cycle，the cycle oil recovery gradually decreases，and oil production tends to be steady. As the huff-puff pressure rises，both the oil production and the oil recovery increase. The study confirms that the huff-puff pressure higher than the formation pressure can improve the oil recovery in Xi233 area Chang7 shale oil reservoir. The development method of advanced gas injection huff-puff is recommended in the study area.