The invention discloses a statement length control method and device, relates to the technical field of Internet, and is invented by aiming at solving the problem that longer statement requests are rejected. The statement length control method comprises the following steps that after an access request is received, the statement length and the rest buffer quantity of the access request are detected; whether the rest buffer quantity is smaller than the statement length or not is judged; if the rest buffer quantity is smaller than the statement length, the access request is processed. The statement length control method and the statement length control device are mainly applied to an SQL (structured query language) database system.