The invention relates to an expandable leakproof well cleanout packer, which comprises an 
upper joint, upper and lower connecting pipes, upper and lower central pipes, a valve ball, a righting block, a 
rubber cup and a leather cup, wherein the 
upper joint is in threaded connection with the upper connecting 
pipe, and the upper connecting 
pipe is in threaded connection with a valve hoop; the valve ball is arranged on a valve ball seat in the valve hoop to form a valve pressure relief device, and the lower end of the valve hoop is in threaded connection with an upper 
reducer joint; the upper 
reducer joint is in threaded connection with the upper central 
pipe, and the righting block is distributed on the periphery of the upper central pipe to form a leaf-hand righting 
pressure release device; the lower end of the upper central pipe is in threaded connection with a short 
coupling, and the movable joint jacket of the short 
coupling is in threaded connection with a lower nipple; the lower nipple is in threaded connection with a lower 
reducer joint, and the lower reducer joint is in threaded connection with the lower central pipe; the lower central pipe is provided with the 
rubber cup and the leather cup in a suspending way, and the lower end of the lower central pipe is in threaded connection with an adapter connector to form a sealed suspending device; and the lower connecting pipe is in threaded connection onto the adapter connector. The expandable leakproof well cleanout packer provided by the invention has the advantages of reasonable structure, short well cleanout time, energy saving and 
environmental protection, and the 
pollution of well cleanout liquid leakage to the formation is effectively prevented.