NOVELTY - An insulation material for a bus comprises 65-85 pts. wt. a bisphenol A type epoxy resin, 0.06-0.11 pts. wt. nano montmorillonite, 15-35 pts. wt. curing agent, 280-380 pts. wt. silicon powder, 0.01-0.05 pts. wt. zinc oxide (ZnO) powder, and 0.05-0.15 pts. wt. barium titanate (BaTiO3) powder.    USE - As insulating material used for bus (claimed), particularly for electric power plant, power station, transformer substation, a photovoltaic power station, wind power generating variable power station, and power device.    ADVANTAGE - The present material has good water resistance; is capable of operating in harsh climatic conditions; is prepared by cost-effective method; has bending strength of 134.6 kJ/m2, and impact resistant strength of 32.1 kJ/m2; is safe and reliable; has dynamic and thermal stability; and has long service life.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation of the insulating material involving: heating bisphenol A epoxy resin at 70-80 degrees C for 30 minutes; heating nano montmorillonite at 70-80 degrees C under vacuum treatment for 120 minutes; adding the processed bisphenol A type epoxy resin, processed nano montmorillonite, silicon oxide powder, ZnO powder and BaTiO3 powder into a ball mill for ball milling, then vacuum de-foaming for 6 hours, and dispersing to obtain primary mixed material (m1), where temperature of the ball mill is set at 70-80 degrees C, vacuum of the ball mill is set is set at 133 Pa and rotating speed of the ball mill is set at 750-850 revolutions per minute (rpm); heating and melting the curing agent at 80-90 degrees C for 30 minutes; mixing the melted curing agent and the mixed material (m1) in a tank, followed by stirring and vacuum de-foaming for 2 hours to obtain second mixture (m2), where the tank has set temperature of 70-80 degrees C, vacuum of 133 Pa and rotating speed of 800-850 rpm; preheating the second mixture for 2 hours at low temperature of 100-120 degrees C and vacuum casting to obtain insulation layer; curing the insulation layer at 160-180 degrees C for 50 minutes; taking out semi-cured insulation layer, followed by second curing at 235-245 degrees C for 120 minutes to obtain solidified insulation layer as finished product.