The invention discloses an approximation method for a traversal and a rate of an ultra-dense network system. The approximation method comprises the following steps: 1) obtaining traversal and rate expressions of an ultra-dense network according to an ultra-dense network system model; and 2) obtaining approximate expressions for the traversal and the rate of the ultra-dense network according to mathematical knowledge such as random geometry and the like. Different from other technical schemes, the approximation method disclosed by the invention considers the influence of noises, so that while a good approximate accuracy under a high signal-noise ratio is guaranteed, the method has better approximate accuracy than other schemes under a low signal-noise ratio environment.