After the industrial revolution, European science and technology developed for hundreds of years, but new China was only established for a few decades. In the ordinary science and technology industry, we need to catch up; A technician for many years, Xie Kai was reborn and returned to the day that changed his life and that of many people. In this life, he no longer intends to accept fate, but to use his knowledge to change the fate of those around him. Changes have enabled the Republic’s military industry to achieve corner overtaking in some areas in advance, and have caught up with the European powers in most areas. Tanks? Rockets? Missiles? Advanced fighters? Nuclear submarines? Aircraft carriers? It has nothing to do with Xie Kai... Technology blockade? Embargo? It's okay, let's find a way... Want Chinese weapons and equipment? This matter...you can talk about it if you have money... What does Xie Kai do? He doesn't even know it. He just remembers, I am a military boy!