This article describes Single-chip AT89S51 and peripheral interface circuits answer system. when the circuit is in normal working condition, after the successful operation through an intuitive digital tube display answer number of successful players. The system uses a single-chip AT89S51 as a core device, the use of buttons as the input signal, and speakers for voice prompts.In order to ensure the effectiveness of answer, answer device also has to prevent violations of the functions of the first operation and the achievement of key lock closure operation.