Abstract: Dialectics of tone has always been the key and difficult point in the promotion of Putonghua in minority areas, and the analysis of tone deviation has become an important link in tone dialectics.Therefore, this paper uses PRAAT Chinese phonetic analysis software, taking preschool children teachers in Guangnan County as the research object, and makes an acoustic analysis of their Mandarin falling-rising and falling tone deviation, and compares the experimental data with the tone pattern of Mandarin.The results showed that tone of mandarin in the native speaker was not enough tortuous and the tone was smooth.The falling tone type shows a slow decreasing trend of falling tone type, and the degree of falling tone decline is insufficient.The main reasons are the negative transfer of mother tongue and the influence of language environment.

Key words: ethnic minority, falling-rising tone, falling tone, deviation