The disclosure relates to a method for making semimetal compound of Pt. The semimetal compound is a single crystal material of PtTe2. The method comprises: placing pure Pt and pure Te in a reacting chamber as reacting materials; evacuating the reacting chamber to be vacuum less than 10 Pa; heating the reacting chamber to a first temperature from 600 degree Celsius to 800 degree Celsius and keeping for 24 hours to 100 hours; cooling the reacting chamber to a second temperature from 400 degree Celsius to 500 degree Celsius and keeping for 24 hours to 100 hours at a cooling rate from 1 degree Celsius per hour to 10 degree Celsius per hour to obtain a crystal material of PtTe2; and separating the excessive reacting materials from the crystal material of PtTe2.