The present invention discloses a vocabulary initialization method and device for multilingual translation based on a graph network, comprising: constructing a vocabulary mapping heterogeneous graph between each language and a core language based on the
decomposition and composition relationship of bilingual dictionaries, words, and word units corresponding to each language; learning the word unit mapping relationship between the word units of different language vocabularies and the core language word unit on the vocabulary mapping heterogeneous
graph based on a heterogeneous graph neural network and a contrastive learning
algorithm; initializing the word units of the core language word unit in a multilingual
machine translation task using the word unit of the core language BERT model, and mapping other languages to the word unit space of the core language BERT model based on the word unit mapping relationship, thereby completing the initialization of all word units in the multilingual
machine translation task. The present invention uses the method of constructing a word unit heterogeneous graph to complete the mapping of word units in different languages to initialize word units, thereby improving the translation accuracy of the multilingual
machine translation model and also accelerating the model convergence speed.