In order to improve the oil displacement efficiency of imbibition oil recovery in ultra-low permeability sandstone reservoirs, water flooding core experiments were carried out to study the effects of imbibition oil recovery process parameters such as injection pressure, injection volume, injection times, soaking time and different surfactants on imbibition oil recovery. The results show that the addition of FH-1 surfactant in water can effectively improve the dynamic imbibition recovery. The imbibition recovery rate increases with the increase of injection pressure and injection volume, but the recovery rate does not increase after the injection volume exceeds 1 PV, and increases with the increase of injection times, but the increase gradually decreases. The imbibition recovery rate is maximum when the soaking time is 48 h. According to the results of indoor simulation experiments, combined with the process parameters optimized by other block construction experience, the field test of imbibition oil recovery was carried out in SL-3 block. After three months of field experiments, the average daily oil production increased by 19 times, the daily liquid production increased by 2 times, and the comprehensive water cut decreased by 58.8%.