彼得 (Bǐdé) is the standard Chinese transliteration of 'Peter,' and
小 (xiǎo, 'little') is added as the affectionate diminutive — exactly like English 'Petey' or 'Little Peter.' Common in translations of children's stories (《
彼得兔》 Peter Rabbit, 《
彼得潘》 Peter Pan) and as a character name in dubbed films.