Abstract: A friction coefficient has been one of the most important indicators in the broad range of applications. The dynamic and static friction coefficients of grains can greatly contribute to the logistics, machine design, safety assessment, and process control in the agricultural and processing industries. The efficiency and accuracy of grain friction coefficients can indirectly influence the development cycle and the design of entire machines. However, conventional single-grain measurement cannot fully meet the large-scale production in recent years. These measurements of grain friction coefficients often rely predominantly on human eye readings, leading to the generally slow acquirement and inaccurate values. In this study, an electro-mechanical integrated device was presented to measure the grain friction coefficient. Structural optimization was also realized to incorporate the previous systems. A turntable collection bin and a single-grain feeding mechanism were introduced to switch the static and dynamic friction coefficient measurement systems using the inclined plane. This modification was used to realize the simultaneous measurement of the static friction coefficient of multiple grains, along with the collection of the number of grains falling at various inclined angles. Consequently, the corresponding static friction coefficient values were weighted and then averaged to yield a static friction coefficient that represented the overall grain particle in practical applications. A seamless transition was also realized for the single-grain dynamic friction coefficient measurements. A photoelectric sensor was employed to detect the sliding of grain particles during static friction measurements, as well as the acceleration and time of fall during dynamic friction measurements. The control system was utilized to automatically calculate and display both the static and dynamic friction coefficients. A measuring device was also constructed for the measurement. A series of experiments were conducted on the wheat with varying moisture contents (ranging from 8.66% to 20.06%) on the stainless-steel plates and white cast iron plates. During the measurement of the static friction coefficient, once the platform angle reached the critical value where the wheat grains commenced sliding, the wheat grains fell along the inclined surface into the turntable collection bin below. The single-grain feeding mechanism more effectively met the measurement requirements of the dynamic friction coefficient. The static or dynamic friction coefficients were measured and then displayed in real time on the screen during each measurement. When the moisture content of wheat was between 8.66% and 20.06%, the static and dynamic friction coefficients between wheat grains and the two contact materials rose, as the moisture content increased. The static friction coefficient with the stainless-steel plates ranged from 0.338 5 to 0.424 9, and the dynamic friction coefficient ranged from 0.154 1 to 0.223 2. The static friction coefficient with the white cast iron plates ranged from 0.385 7 to 0.488 0, and the dynamic friction coefficient ranged from 0.162 2 to 0.254 1. The range and trend of data were similar to the theoretical prediction. Furthermore, the dual device was converted into the traditional manual and the automated mechanical measurement. Simultaneous measurement of the static friction coefficients was realized for the multiple tested materials. The measurement experimental board and single grain feeding rotor can be conveniently replaced as needed, in order to rapidly and precisely measure the static and dynamic friction coefficients of grains. This finding can provide a strong reference for the high design level and performance of planting, harvesting, and post-harvest processing equipment.