The invention discloses a method for answering questions in the petrochemical field based on a knowledge map, which comprises the following steps: constructing conceptual knowledge map and entity knowledge map; receiving the question input by user, segmenting the question, extracting entity, attribute, relation and restriction condition, abstracting the entity into concept, matching the question template and transforming it into structured query statement; query conceptual knowledge map and entity knowledge map, generate answers, match answers to answer sentences template, and transform them into natural language answers. The invention also discloses a petrochemical field question answering system based on knowledge map. The invention can store and express the knowledge in the petrochemical field in the form of knowledge map, establish the connection between the business requirement and the development and production data, provide convenience for the user to obtain the professional knowledge in the form of natural language interactive question answering, improve the user experience, and help to provide the work efficiency of the user.