Abstract: A binary code similarity detection device performs a preprocessing operation of generating an assembly expression for the binary code by converting a machine language of an input binary code into an assembly language, extracting an assembly function or a command from the binary code converted to the assembly language, and detects a similarity to the assembly expression of a pre-stored binary code by inputting the assembly expression generated by the preprocessing operation to a trained model based on bidirectional encoder representations from transformers (BERT), and the trained model is generated by performing a pre-training step of causing the assembly expression to be understood and a fine-tuning step of inputting an assembly expression of a first binary code and an assembly expression of a second binary code to a pre-trained model and then fine-tuning the pre-trained model based on a similarity between the first binary code and the second binary code.