The invention discloses a method for 
casting a valve body of a heavy-calibre non-rising-stem flat valve. In the method, ester-cured water-glass sand is used for modeling to make a sand core, two RND 300 neck-down heating heat-insulation dead heads (1) are arranged at the valve belly part of the valve body of the sand core, six shaped 
chills (4) which are 90mm thick are arranged at the bottom of the valve belly part at a distance of 30mm, eight shaped 
chills (3) which are 70mm thick are arranged at an edge 
flange of the valve body, and a Phi 200*50mm shaped chill (2) is installed at the 
tail part of the valve body; the neck-down heating heat-insulation dead heads (1) perform feeding on the valve belly part of the valve body, the shaped 
chills (4) perform feeding on the bottom of the valve belly part, and the neck-down heating heat-insulation dead heads (1) at the valve belly part perform feeding on the shaped chills (3) of the edge 
flange of the valve body, and the shaped chill (2) performs feeding on the 
tail part of the valve body. In the invention, the neck-down heating heat-insulation dead heads are used for feeding, convenience is brought for gas 
cutting, the 
casting yield is increased, 
casting defects, such as sand inclusion, 
shrinkage porosity, cracks, sand blowholes, 
slag blowholes and the like, are avoided, and technical demands of customers are met.