The matrix permeability of shale oil reservoirs is extremely low,and gas huff-n-puff is an effective technology for enhanced oil recovery(EOR)of shale oil. Due to artificial and natural fractures,field tests showed that gas channeling from adjacent wells was serious during huff-n-puff gas injection. Injecting foam can reduce gas fluidity,increase the swept volume of huff-n-puff,and inhibit the gas channeling between fractures. Four foaming agents were screened through laboratory experiments. The foaming ability and foam stabilization were evaluated to select the foaming agent with the best comprehensive performance,and then the gas channeling law during huff-n-puff gas injection in the fractured shale core was explored. In addition,the plugging performance in the fractured core after foam injection was studied,and the potential of foam channeling control for EOR by huff-n-puff gas injection in shale cores was explored. The results demonstrate the AOS foaming agent with a mass fraction of 0.4% shows the optimal stability;the pressure difference of foamed gas plugging generated after the simultaneous injection of gas and liquid grows to 6.67 MPa,and the gas breakthrough time increases by 13.72 times;based on foam plugging,five cycles of huff-n-puff can enhance the total recovery factor by 6.58%.