[Introduction] When I think of the fighting years when I defended the southern frontier of my motherland, I can't calm down for a long time. I often dream that I am back on the battlefield, fighting side by side with my comrades-in-arms; I often recall the looks and laughter of my comrades-in-arms, and remember training, studying, living and fighting with them. However, some of them have already passed away, using their lives and blood to build the gateway to the south of our country. Last summer, due to Comrade Li Yuqian of the PLA Daily shooting a TV documentary "Life-and-Death Brother Company", directors such as Liu Xueliang went through Beijing, Shandong, Anhui and other places, and found me 25 years ago in the lost Laoshan battlefield diary at the home of my Shandong comrade Hou Liuwen. This diary reflects my true feelings and combat experiences at the time, and when I took it back from Liu Xueliang's hands, the memory was refreshed again clearly, and I couldn't help but recall the smoke-filled battlefield. The comrades-in-arms who shared life and death appeared before my eyes again. I couldn't help picking up the pen, organizing my thoughts, and recording these unforgettable fighting years to express my deep longing for my comrades-in-arms. Here, I would like to express my sincere gratitude to comrades such as Li Yuqian and Liu Xueliang who helped me find this diary again! Salute to them!