Abstract: In view of problem that single influencing factor can not fully reflect cutting head load and its fluctuation variation law in existing research methods of cutting head load characteristics for roadheader, by analyzing instantaneous load of cutting head, the main influencing factors on cutting head load of longitudinal roadheader under horizontal cutting condition were determined， including cutting rock character, slotting depth, cutting depth of cutting head, rotating speed of cutting head and swing speed of cutting boom. For horizontal cutting condition of a longitudinal roadheader, a comprehensive simulation analysis of various factors that affect cutting head load was carried out using Matlab, and variation laws of cutting head load and its fluctuation with various factors were obtained: the load of the cutting head increases with the increase of the Protodyakonov coefficient of the rock faces, and the increase of the lateral resistance is particularly obvious. The degree of lateral resistance fluctuation is higher than the others, and it decreases with the increase of the Protodyakonov coefficient of the rock faces. As the slotting depth increases, the load in each direction of the cutting head increases approximately linearly and the lifting load increases most, and the load fluctuations in all directions decrease with the slotting depth increases. With the increase of the cutting depth, the cutting head load generally increases, and the degree of load fluctuation decreases. Under the condition that the rotating speed of the cutting head is constant, the cutting head load increases with the increase of the cutting boom swing speed. At the same swing speed, the cutting head load increases with the rotating speed of the cutting head decreasing. The lateral resistance fluctuation is significantly higher than the lifting and propulsion resistance fluctuations, the lateral resistance and propulsion resistance fluctuations change according to the cutting head load law, and the lifting fluctuation is opposite. The variation law of the load fluctuation is not consistent with that of the cutting head load, and sometimes even conflicts with each other. Therefore, the operating parameters(slotting depth,cutting depth) and motion parameters (cutting head rotating speed and cutting arm swing speed) of the cutting head should be selected reasonably during operation of the roadheader, so that the parameters can be matched with each other to reduce the roadheader vibration and extend life of the roadheader.