I am a special soldier. Where was it filmed?

I am a special soldier, shooting mainly in four locations. The main shooting location is Nanjing Military Region, Jiangsu Province. For example, Grandpa's military compound is a cadre retreat in the Nanjing Military Region, the suburb of Erniujia is the suburb of Jiangning District, and Yan is a shanty town in the southern suburbs of Nanjing. The training ground was shot in Chengdu Military Region, and some scenes were shot in Hainan, but few in Hainan Island, and most of them were shot in Chengdu. Then, several urban scenes, Nanjing, Chengdu and Hainan, are uncertain.