Highway construction site project involves a complex interplay of various construction processes and a dynamic construction environment, which is dangerous for workers. The occurrence of highway construction safety accidents will lead to significant losses on society and enterprises. Therefore, it is of great significance to analyze the causes and prevention methods of highway construction safety accidents in China. This study collected 123 accident cases of highway construction and established the framework of highway construction accident cause based on the 4 M model. Then, Statistical analysis is conducted to reveal the general rules of accident occurrence. It is observed that management factors are the main causes of accidents and “Inadequate training” occurs most frequently in management factors, which can provide reference suggestions for relevant enterprises and government departments.