In order to identify and evaluate the rock wettability of shale oil reservoirs and deepen the understanding of the crude oil producing in the reservoirs，this paper takes rock samples from the shale oil reservoirs in the West 233 area of Ordos Basin as the research object and carries out two-dimensional nuclear magnetic resonance（NMR）T1-T2 map measurement as well as spontaneous imbibition wettability experiment based on NMR technology in the state of fully saturated water and irreducible water. In addition，the paper establishes the basic method for evaluating wettability based on the two-dimensional NMR T1-T2 maps and selects parallel rock samples for core water flooding experiment based on NMR technology，so as to analyze and evaluate the influence of wettability on the crude oil production characteristics during the water flooding. The research results show that after the oil flooding water（i.e.，in the irreducible water state），the force between the water and the pore throat wall is significantly reduced，and the water exhibits the characteristics of bulk relaxation in the state of free fluid in the pore throat space. As a result，the wettability of the rock samples is oil-wet，which is consistent with the results of the spontaneous imbibition wettability experiment based on NMR technology. Therefore，it can be seen that the wettability of the rock samples can be evaluated by comparing the two-dimensional NMR T1-T2 maps in different states. During the water flooding，the crude oil is mainly produced in the medium and large pore throats of the rock samples but poorly produced in small pore throats. When the capillary number of injected water is increased，and the oil-wet characteristics of the rock in reservoirs are weakened，the crude oil producing in the small pore throats is significantly improved.Therefore，the capillary number of injected water and wettability of the rock should be comprehensively considered during water flooding development，so as to improve the water flooding efficiency of shale reservoirs.