The invention provides a user facility P-P communication method which is applied in a cellular network communication system, the method comprises the following steps: utilizing frequency spectrum resource of a cellular network to establish P-P communication link circuit between a first user facility and a second user facility which are in the same district of a cellular network, and the first user facility and the second user facility utilize P-P communication link circuit to communicate. The invention also provides a cellular network communication system, which comprises a base station and auser facility, the user facility is used to constitute mutual communication link circuit through the relay of a the base station, and the user facility is also used to constitute mutual P-P communication link circuit, which utilizes P-P communication link circuit to execute P-P communication. The invention can improve frequency spectrum resource utilization efficiency of cellular network communication systems and can lighten the burden of the base station.