The invention discloses a preparation method of high-strength electroceramic. The preparation method includes the specific technological steps that 1, the high-strength electroceramic is prepared from, by
mass, 20-30 parts of calcined
bauxite, 20-30 parts of
mullite, 20-35 parts of high plastic clay and 15-25 parts of
feldspar; 2, after all raw materials in step 1 are mixed, water is added, ball-milling is conducted, and
slurry is obtained; 3, the
slurry is subjected to sieving and
iron removal, and mud cakes are obtained after pressure
filtration dehydration; 4, the mud cakes are subjected to aging for over 24 hours after coarse milling, then the mud cakes are extruded into electrical porcelain wet billets of the required sizes through a vacuum deairing
machine, and green bodies are obtained through fettling and
drying; 5, the green bodies are placed in a drawer type or tunnel type
kiln and sintered at the temperature of 1260-1330 DEG C for 24-48 hours; then cooling is conducted, and high-strength electroceramic products are output from the
kiln. The high-strength electroceramic material is wide in
raw material source, good in process performance, low in manufacturing cost and particularly suitable for being used for manufacturing high-strength porcelain insulators used for extra-
high voltage and super-
high voltage power
transformer lines and power stations.