2019at the 2019 international rail transit technology exhibition, li yanfeng, lin zhenyi and tan jingzhou, core members of the r&d team of jac group, brought the latest high-speed emu "jiangcheng star" to a high-profile appearance. ccc。 time goes back to 2015 when the high-speed rail is developing rapidly. due to the two-year joint venture negotiations with menzel company, jac group decided to let the project team led by lin zhenyi test drive three months in advance to win the order of ryansi. at the same time, li yanfeng, who was studying at ryanxi university, became the driver of this test drive by chance, and recognized that the person in charge of ryanxi's test drive was lin zhenyi, his crush on his childhood crush, but unexpectedly, the test drive failed. li yanfeng followed lin zhenyi back to china, and lin zhenyi was devoted to tan jingzhou, the leader of the young generation of jac. after returning to china, li yanfeng secretly helped lin zhenyi to repair the locomotive and helped jrc repair the shanghai urban rail locomotive. at the same time, tan jingzhou and menzel had fought wits and courage for a long time. menzel questioned jrc using the menzel technology mastered by li yanfeng to repair the shanghai urban rail locomotive, and proposed non-competitive additional clauses in the negotiations, which made tan jingzhou and jrc unacceptable. the jrc employee, who urgently needed to prove his own value, took over the order for high-speed train manufacturing in yunlai country under the leadership of lin zhenyi. li yanfeng also followed him all the way to pursue love. yunlai country is almost frustrated and extremely unsuitable for high-speed train operation. in order to successfully obtain the order, li lin and the other two overcame many difficulties, not only achieved technological breakthroughs, but also showed signs of their emotions. after experiencing incidents such as ryanxi test drive, yunlaiguo orders, and subway locomotive repairs, jac group made up its mind to stop the joint venture negotiations with menzel and unswervingly follow the path of independent research and development. the yunlaiguo project has finally succeeded after many difficulties, which has overall enhanced the international popularity of china's jac locomotive technology and attracted international attention. at this time, a bigger problem was placed before jrc - fully realizing the speed-up of trains (jiangcheng star), gathering outstanding scientific researchers from all walks of life to overcome technical difficulties, successfully break through a series of world locomotive technological innovation problems such as bogie technology and motor technology, and achieve a great speed-up of our country's trains, step by step leading jrc high-speed railway to the peak of the world's technical stage, and proving to the world the strong strength of china's independent research and development technology.