Based on the roadway local resistance calculation formula, the differential calculus theory and the method of theoretical derivation were used to acquire the new local resistance formula which applied to tapered roadway, then compute the local resistance with the tapered roadway parameters. A numerical local resistance through simulating the tapered roadway by Fluent was obtained, by comparison, it turned out that the local resistance which obtained through the new formula was consistent with the numerical local resistance. It proved that the new formula could be used to solve the local resistance of tapered roadway, it was also a considerable practical method to solve roadway problem.