This paper investigates the function of each step of pharmaceutical information consulting service system. Alternative answer e (knowing the general information of the questioner and the background information of the question) helps the pharmacist to clarify the question being asked. B (literature evaluation, analysis and arrangement) is the most important consulting service step in drug information service. Without this step, the answer to the question can only be simply copied drug information. C (establishing an effective retrieval method and consulting literature) is a step to quickly and accurately obtain the answers to questions. Alternative answers A and D have no corresponding questions.