As an important hub connecting the cutting arm and the body of the roadheader, the dynamic characteristics and reliability of the rotary table are the key to improve the cutting speed. In this paper, the dynamic characteristics and structural optimisation of the rotary table are studied, the explicit dynamic model of the cutter tooth cutting hard rock is established to obtain the cutting load force; the rigid-flexible coupling model of the whole machine is constructed, and the dynamic characteristics of the rotary table under different working inclination angles are studied; the structural bionic optimisation of the rotary table is carried out by referring to the structure of the human femur. The results show that the roadheader is the most stable when cutting in the downward direction, and the stability of the machine body will be affected if the cutting arm is lifted too high. The force on the upper articulated hole of the rotary table is the main reason affecting its dynamic characteristics. The upper articulated hole mainly bears the support force during cutting, and the lower articulated hole mainly bears the normal force of the coal rock plane. The equivalent force of the optimised rotary table is reduced by 33.072% and the deformation is reduced by 2.122%. This study is of great significance to the rapid boring and optimised design of roadheader.