Badaling Great Wall Station, located 102 meters under the core area of the Badaling Great Wall, is the deepest high-speed railway station in the world.

"Pressure differences at the station can reach 11,000 Pa," he said. "The train will pass at 350km per hour, which is a great challenge for the comfort of the train."

Finally, the team solved the problem via the combination of air tightness and pressure control technologies after countless debugging.

"The new train marks China's high-speed rail has entered the intelligent era," said Zhu. "The Fuxing family has formed a series of products, which can adapt to the needs of various operating environments such as plateaus, high cold, humid heat, wind and sand."

"It also provided us valuable experience during the following development of trains," he said. "We are striving to make more contributions to our country's high-speed railway construction."