Some information:

The film depicts the story of the North Korea-allied Chinese People's Volunteer Army, forcing U.S. forces to withdraw in a fictionalized retelling of the Battle of the Chosin Reservoir during the Korean War.

The Battle at Lake Changjin is the most expensive film ever produced in China, with a budget of $200 million. The film grossed $913 million at the worldwide box office, making it the second-highest-grossing film of 2021, the highest-grossing Chinese film of all time, the highest-grossing non-English film, and the second highest-grossing film in a single market.

And some good Anglos:

Reviewing for Forbes, Scott Mendelson said "It’s arguably no more jingoistic, at least until the final montage, than (offhand) Pearl Harbor or We Were Soldiers." He further described the film as spectacular with its "copious mass battle sequences and intricate action set pieces" against what was a "pretty dry war picture" and a "generic war actioner" when compared with The Eight Hundred.

Reviewing in The Independent, Louis Chilton wrote that, while it was fair to describe the film as propaganda, the same criticism should be directed at similar American films such as American Sniper or Captain Marvel.