The present invention relates to the technical field of reservoir description in oil field development, in particular to a fracture-cavity inter-well communication passage and flow parameter characterization method. The method comprises the following steps of: (A) establishing an analytical expression of describing a fracture-cavity reservoir inter-well flow rule; (B) establishing a tracing production concentration curve fitting mathematical model; (C) performing curve fitting model solution; and according to principles of the three steps, compiling fracture-cavity reservoir tracing curve fitting software, performing fitting on a theoretical tracing curve and an actually measured tracing curve by a method of adjusting a parameter on a software interface, and simultaneously carrying out calculation to obtain mass mik, a flow velocity vik, an orifice area Aik and a flow duct length lik of a fracture-cavity injection tracer so as to implement characterization on a communication passage and a flow parameter. According to the present invention, an established model of describing the flow rule of the fracture-cavity reservoir tracer further accords with the true situations; quantitative calculation characterization on the fracture-cavity reservoir inter-well communication passage and the flow parameter is implemented; and in the fitting process, automatic fitting of a computer and parameter regulation of a worker are combined.