The invention discloses a 
defect repair method of a high-temperature 
alloy casting, and belongs to the technical field of 
precision casting of metallurgical 
casting. A defect communicated with the surface of the 
casting is changed into a closed defect by using 
electron beam surface blocking, and then 
hot isostatic pressing is performed on the closed defect, so that the qualification rate of the casting is improved. The 
electron beam surface blocking process comprises the following steps and control technical parameters: detecting through 
visual contact, 
fluorescence and X-
ray to determine a loose region and level; 
machining a square or circular groove with an area of being greater than that of the defect and depth of 3-5 mm on the surface with the defect of the casting if a defect beyond tolerance communicated with the surface exists; 
machining a matchable cover plate with thickness equal to that of the groove and gap of 0.1-0.5, placing the cover plate on the groove and spot-
welding at 3-4 positions by using 
argon arc welding for fixation; sealing and 
welding the cover plate at the groove of the casting by using an 
electron beam under the condition that the vacuum degree is 10<-4> to 10<-1> Pa. The method has the advantages that the electron beam surface defect blocking and 
hot isostatic pressing defect closing are combined, the effectiveness for repair of the casting through the 
hot isostatic pressing is improved, and the method can be used for producing high-temperature 
alloy composite members.