In the Parikh and Wilczek’s tunneling framework，Hawking radiation of charged particle in the Gibbons-Maeda dilaton black hole is investigated. When a particle with electromagnetic charge tunnels across the event horizon，energy conservation and electromagnetic charge conservation of the spacetimes are emphasized and the back-reaction effects of the charged particle are considered.The present results show that the tunneling probability is related to the difference of the Benkenstin-Hawking entropy of the black hole.This implies that black hole radiation is consistent with information conservation and the underlying unitary theory.