This paper explores the possibility of experimentally testing the viscosity of dark matter fluids in laboratories on Earth's surface. From the theoretical calculation results, the viscous force of dark matter fluid and gravity are basically the same order of magnitude as the gravitational force. At the same time, because the experimental devices for measuring the gravitational constant are very precise and can accurately sense changes in gravity, we believe that the existing experimental devices for measuring the gravitational constant can be used to measure the viscosity of dark matter fluids. Since the experiment is carried out on the ground, it is convenient to control various parameters artificially. In this paper, the influence of the viscous force of dark matter fluid on the measurement results of gravitational constant is discussed by analyzing the existing experimental device for measuring the gravitational constant by the angular acceleration feedback (AAF) method. This paper argues that in some current experiments on measuring the gravitational constant by angular acceleration feedback methods, the influence of the viscous force of dark matter fluids has been ignored. If the influence of the viscous force of dark matter fluid is taken into account, the problem of inconsistent results of different experiments can be better solved. After the introduction of the viscosity of dark matter fluids, the upper and lower limits of the gravitational constant (HUST-19) measured by the angular acceleration feedback method of Huazhong University of Science and Technology can be extended to 6.674351×10^(-11) m^3·kg^(-1)·s^(-2) and 6.674551 × 10^(-11) (m^3·kg^(-1)·s^(-2) ), which can improve the inconsistency with the time-of-swing method results to a certain extent.