The invention relates to an automatic route planning method in assembly process BOP (bill of process) scheme. The method comprises the following steps of: establishing a BOP case source library; extracting information of each part in the to-be-planned assembly body, and establishing an inter-part connection relationship matrix according to whether connection relationships exist among the parts ornot; when it is judged that the similarity matching value of the to-be-planned assembly body and the local case is higher than a set threshold value, parts, with the similarity matching value of the to-be-planned assembly body higher than the set threshold value, in the local case are combined into a component; obtaining an attribute matrix and a connection relationship matrix of the part and/or the component, and determining a basic part of the to-be-planned assembly according to the attribute matrix of the part and/or the component; and determining a hierarchical assembly sequence of the parts and/or the components according to the distances between the parts and/or the components and the basic part, and planning a route in a BOP scheme of the to-be-planned assembly body. The route planning time of the same or similar BOP schemes is reduced, and the BOP schemes are stored, retrieved and reused.