In order to solve the problem of ignition and flame spreading in axis of long-chamber charge in the large-caliber gun,a multi-point system was designed to research for charging the long charge-chamber of which the length is more than 3 meters. The high-speed camera was used to study the igniting consistency. Results show that C igniting is ignited in 4 ms,and the consistency is better than A and B igniter. The p-t curves in different lengths of multi-point ignition tube are measured,the results show that the p-t curves of two parts and four parts simulation equipment are almost superposition,the p-t curves ascend consistently before the diaphragm broke,with good igniting consistency. The feasibility and reliability of the technology in long-chamber charge are validated by the experiment.