The invention discloses a process for an integral multiple-step multistage heat preservation 
sintering of a metallic 
porous membrane tube, which comprises the following steps: step one, 
processing a 
flange according to the inside 
diameter size of a tube blank of a processed and formed metallic 
porous membrane tube, and assembling the 
flange and the tube in tight fit; step two, furnace charging, which is to charge the assembled metallic 
porous membrane tube with the 
flange into a vacuum high temperature 
sintering furnace to perform 
sintering; and step three, sintering, which comprises the following steps: the stage for water 
evaporation, the volatilization initial stage of a 
sol dispersant, the volatilization 
intermediate stage of the 
sol dispersant, the volatilization final stage of the 
sol dispersant, the stage of temperature rise, the stage of presintering shrinkage, the stage of sintering, and the stage of temperature reduction. The process has reasonable steps, is simple and convenient to operate and control, and can effectively overcome the problems of 
heat affected zone generated by an 
argon arc welding between the metallic porous membrane tube and the flange, and peeling, shedding and the like generated by a 
metallic membrane layer in the sintering process.