For the optimization of experimental conditions of electrolysis of saline water and hydrochlorine fuel cell, the effects of four factors, including electrolysis voltage, electrolysis time, electrode spacing and electrolyte concentration, on the energy conversion efficiency of hydrochlorine fuel cell were investigated by orthogonal test. The results showed that the optimized experimental conditions for the electrolysis of saline water were: electrolysis voltage of 8 V, electrolysis time of 6 min, electrode spacing of 1 cm, and electrolyte concentration of 15%. The buzzer loaded on the hydrochlorine fuel cell operated for 4.25 min under these conditions, and the experimental conditions were reproducible, which is suitable for students' experiments in secondary chemistry and elementary science, as well as for family fun experiments.