Entanglement percolation of quantum small-world networks in mixed state is investigated by means of generating function and entanglement swapping method. Based on theoretical calculation and numerical simulation, the relationship between normalized average component size and path length in small-world networks is analyzed. Results show that the small world networks have a larger average component size under the shorter paths in small-world network. It is further demonstrated that quantum small-world networks have larger aggregation and shorter average paths. It is found that the average component size increases with the increase of fidelity, and increasing the average degree of small-world networks can reduce the fidelity required for information delivery. The fidelity of maximum entangled states can be improved by entanglement swapping of mixed states, which shows that entanglement swapping can optimize the entanglement percolation in quantum small-world networks.