Abstract: In view of problems of large impact of coal plow system under starting and braking condition，dynamic model of the coal plow system was established comprehensively considering factors of sprocket wheel polygon effect, horizontal vibration of drive sprocket shaft, and coupling characteristics between driving device and plow chain. Dynamic characteristics of the system under condition of starting, braking and reverse starting after braking were analyzed by numerical analysis method, and vibration characteristics curves of the front and rear chain tension were obtained. The analysis results show that the system dynamic characteristic are the most stationary by using reverse "S" start scheme, the method is more advantageous to the coal plow system; the nearer the distance between the plow head and the machine head is，the larger plow chain tension impact is; due to time difference between nose and tail of the machine, tension in the front and back end of the chain has a great impact in the starting process; the plow chain tensions produce difference because of uneven distribution after the coal plow system barking，the plow chain tension of the front end has great impact at the reverse restart moment, and it falls with the starting process. The research results provide theoretical basis for designing reasonable start and brake system of the coal plow.