Changing the wettability of reservoirs near condensate gas wells is an effective method to reduce condensate plugging. The crystal structures，surface functional groups，surface morphology，and particle sizes of Fe ₃ O ₄-PT nanoparticles are characterized by the coprecipitation method based on the synthetic polythiophene encapsulated Fe ₃ O4 nanoparticles（Fe ₃O ₄-PT）. Through experiments of static wetting contact angle measurement，static imbibition，single-phase flow，and two-phase flow，this paper studies the changes in rock wettability，water oil imbibition，single-phase flow before and after nanoparticle treatment，and the change characteristics of gas-oil two-phase relative permeability curves. Additionally，the feasibility of Fe ₃ O ₄-PT nanoparticles to improve reverse condensate plugging is comprehensively evaluated. The experimental results show that the polythiophene coating will not change the original structure of Fe ₃ O4 nanoparticles but enhance the original diffraction peak intensity. The average particle size of Fe ₃ O ₄-PT nanoparticles is 17.2 nm. After nanofluid treatment，the wettability of rock changes from liquid wetting to gas wetting or neutral wetting. The contact angle between water and condensate on the rock surface first increases and then decreases with the increasing nanoparticle concentration，and increases with the rising temperature. However，it is little affected by pressure and decreases with the increase in salt concentration. The water and condensate imbibition volumes decrease 69.2% and 64.3% respectively. The maximum pressure drops in single-phase water drive or oil drive are reduced by 28.9% and 46.7% respectively. In two-phase flow，the gas-oil two-phase co-permeability areas widen and the isotonic points shift to the upper left. The irreducible water saturation and remaining oil saturation decrease，and the two-phase relative permeability increases significantly. Fe ₃ O ₄-PT nanoparticles can reduce the imbibition efficiency and flow resistance of water and oil，increase condensate fluidity，and improve gas and oil production，thus effectively improving reverse condensate damage.