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【摘要】This paper describes the detailed design of data acquisition device with multi-channel and high-precision for aero- space. Based on detailed analysis of the advantages and disadvantages of two common acquisition circuits, the design factors of acquisition device focus on accuracy, sampling rate, hardware overhead and design space. The mechanical structure of the system is divided into different card layers according to different functions and the structure has the characteristics of high reliability, convenience to install and scalability. To ensure reliable operation mode, the interface uses the optocoupler iso- lated from the external circuit. The transmission of signal is decided by the current in the current loop that consists of opto- couplers between acquisition device and test bench. In multi-channel switching circuit, by establishing analog multiplexer model, the selection principles of circuit modes are given.