The invention provides a fired mold low-
pressure casting process of an integral type compressor 
impeller. The process comprises the following steps of preparing 
coating with silica 
sol binder for fired mold 
casting, wherein a 
fireproofing surface layer and a second layer are made of fused 
alumina powder and sand, and a reinforced layer is made of 
mullite powder and sand special for fired mold 
casting; when 
coating the 
coating on the reinforced layer, adopting a two-time 
slurry staining method, i.e. firstly 
staining thin coating and secondly 
staining thick coating; and after dewaxing a shell, 
roasting at the low temperature of 500 DEG C, storing, and 
roasting at high temperature before pouring, wherein the temperature of high-temperature 
roasting is 1000 DEG C, the heat preservation time is 4h, and the temperature of the shell during pouring is 100-150 DEG C. The prepared shell is high in strength, low-pressure pouring can be carried out by utilizing a single shell, the pouring temperature of molten aluminum is 670-680 DEG C, the mold-filling pressure is 0.03 MPa, the mold-filling time is 10s, the solidification holding pressure is 0.35 MPa, and the holding pressure time is 5min. The integral type compressor 
impeller produced by adopting the fired mold low-
pressure casting process is good in mold-filling and feeding effect, compact in 
casting tissue, good in product 
mechanical property and inner quality, high in production efficiency, and low in labor intensity, and has no need to be modeled through binning.