The invention relates to a drilling hole 
reamer with hydraulic double effect used in 
well drilling of 
petroleum and 
natural gas, comprising a central tube, a body, a knife wing, a valve flake, a spring, a bend, a 
nozzle, a sealing ring, a 
crank and a 
cutting teeth. The body is connected with a 
drill stem by a thread connection. The technical proposal is that: the knife is embedded outside the body and is connected with the body by a pin roll connection; the central tube is arranged in the body; an overflow opening and the valve flake are arranged in the central tube and connected together by a spring. Under 
normal displacement work condition, overflowing area between the valve flake and the overflowing opening is large; the overflowing area is reduced when the displacement is enlarged andthe central tube is driven to downlink by 
differential pressure, and the knife wing is open to work by the 
crank arranged on the knife wing, at the moment the 
cutting tooth is cleaned by partial 
slurry passing through the bend; when the displacement is reduced, the central tube is driven to uplink by thrust of the bottom spring and then the knife wing is reset. The drilling hole 
reamer with hydraulic double effect used in 
well drilling of 
petroleum and 
natural gas has the advantages of simple structure, high functional reliability, less loss of pressure consumption, balance load of the knife wing, usage along with the drilling or the single and usage in 
well drilling construction of a bore hole wall with reducing 
diameter, collapsing block or blocking well condition.