In order to test the voltage and current characteristics of lithium titanate battery under high-rate discharge condition conveniently and fast, a high-rate discharge test system for non-isolated lithium titanate battery based on single-chip microcomputer is designed, whose discharge current rate is about 100C. Single-chip microcomputer is regarded as the control core, and the voltage and current of the lithium titanate battery during the discharge process are collected in a non-isolated sampling circuit. Based on satisfying the sampling accuracy, the voltage and current curves of lithium titanate battery under high-rate discharge condition is obtained with low cost. At last, the curves from the oscilloscope are compared and analyzed to verify whether the accuracy of sampling results about the system and the desired design goals are reached. In addition, the fully automatic cycle test of high-rate discharge about the lithium titanate battery is also proved.