The basic principle of the strapdown inertial navigation accelerometer signal acquisition unit is proposed in this article firstly. The acquisition unit is analysed in many error characteristics, such as the bias stability and the scale factor stability. The main targets of the acquisition unit is presented, then the performance of essential components which conclude sampling resistance, operational amplifier, reference voltage, ADC , and their influence of acquisition unit are studied on. The high accuracy accelerometer acquisition unit should be realized on the design of circuit and the selection of essential component. The acquisition unit is tested on the condition of design, and the test result is analysed. The test results show that, the performance of the accelerometer signal acquisition unit is fit for the acquirement.