Analysis: If Xiao Liu said "I am 22 years old" is true, Xiao Li said "Xiao Liu is 23 years old" is not true; The other two sentences of Xiao Li should be true. "Xiao Chen is 3 years older than Xiao Liu" means that Xiao Chen is 25 years old; Then it is wrong for Xiao Liu to say that he is two years younger than Chen Xiao and 1 year older than Xiao Li, so Xiao Li is 2 1 year old; In this way, Xiao Chen said that "Xiao Li is three years older than me" and "Xiao Li is 25 years old" are all lies; If you don't meet everyone, just say one wrong sentence; Therefore, Xiao Liu is not 22 years old. The other two sentences he said, "2 years younger than Chen Xiao" and "older than Xiao Li 1 year", are true. Suppose Xiao Li says Xiao Liu is 23 years old, then Xiao Chen is 25 years old and Xiao Li is 22 years old, then Xiao Chen is wrong to say Xiao Li is 25 years old; It is wrong for Xiao Chen to be three years older than Xiao Liu; Then substitute them respectively for verification, and the answers meet the requirements; And come to a conclusion.

Answer: Solution: The three wrong sentences are: Xiao Liu said I was 22 years old and Xiao Chen said Xiao Li was 25 years old. It is wrong for Xiao Chen to be three years older than Xiao Liu;

Their ages are: Xiao Liu is 23, Xiao Chen is 25 and Xiao Li is 22.

So the answer is: 23, 25, 22