Abstract: In order to improve the applicability of trackless auxiliary transportation vehicles in underground coal mines, based on the research of various trackless auxiliary transportation vehicles in the current market and the status quo of the auxiliary transportation roadways in coal mines, it is proposed that when designing the auxiliary transportation roadway in the coal mine, the design of underground auxiliary transportation roadways should be based on the systematic design of cross section, pavement, slope, convex variable slope rounding, concave-shaped variable slope rounding, turnout widening, turning and rounding radius of different roadway angles, etc., in order to meet operating environment of vehicles in coal mines.In this paper, based on the parameters of various types of vehicles, various turning radius, ground clearance, wheelbase, approach angle departure angle and other parameters, considering the safe clearance of vehicle operation, the author puts forward the calculation formula of the radius of the fillet required when different types of vehicles turn at different roadway angles,the calculation formula for the rounding radius required at the turning of the roadway and the calculation formula for the rounding radius required at the variable slope connection when different vehicles pass through convex and concave variable slopes. Taking the human carrier,material carrier,shovel truck,framework support carrier produced by Shanxi Tiandi Coal Machinery Equipment Co., Ltd. as an example, using the derived formulas for calculating the corner radius of the turning and the variable slope radius when the angle of the roadways is 45°, 90° and 135°and the applicable rounding radii of various models have been calculated respectively, the angles of the concave and convex slopes are 18°, 22°, 24°, 30° and 40°. The rounding radii applicable to various vehicle types have been measured and calculated, and the calculation results have well met the operating conditions of the vehicle when turning and changing slopes.