Abstract: Higher requirements are put forward in the mechanical sampling system because of complex coal sources and quality in the four coal ports in North China.Designed the sampling system through the research of coal quality of the four coal ports in North China,expounds the system process,introduces the composition of system equipment,power supply and control system,industrial television monitoring system,and the working principle and performance parameters of the component parts,summarizes the technical features of this system.Third-party accreditation body does performance evaluation tests respectively to the unloading and loading sampling systems applied in a northern port of China,and get the test results of systematic bias and precision.Test and industrial operation results show that:system is able to complete mechanization sampling work to large size,high moisture content,high-ash coal,systematic bias and precision have met the national standard requirements,improved the coal mechanization sampling rate of unloading and loading.