A variety of small resistance measurement methods are studied in this paper and improvement suggestions are proposed to solve the problems and interferences in measurement, and the lack of methods. A small resistance measurement device based on the four-line method is adopted to avoid the effects of the feeding line, the temperature and the auxiliary elements on the measurement precision, so as to improve the measurement accuracy of the small resistances. According to the experimental data, it can be directly found that the measurement errors are reduced, and it is verified that the improvement has practical significance on accurate testing of small resistances.