The invention discloses a disassembly and assembly tool for a float valve core and a float valve using the same. The disassembly and assembly tool for the float valve core comprises a rotary handle, aconnecting rod, a righting ring and a cross wrench, wherein the rotary handle is connected to the top end of the connecting rod, the cross wrench is connected to the lower end of the connecting rod,and the connecting rod between the rotary handle and the cross wrench is provided with the righting ring. The disassembly and assembly tool is low in manufacturing cost and convenient to use; and theexternal thread float valve core which is installed by the disassembly and assembly tool and an internal thread float valve joint do not generate a series motion, so that abrasion between the externalthread float valve core and the internal thread float valve joint is avoided, the service life of the float valve is prolonged, and the safety of a downhole tool and the well control safety are moreeffectively guaranteed.