The utility model discloses a portable dual-flat-arm floor type derrick, which comprises a tower body, wherein the upper part of the tower body is provided with leading-out beams, and two hoisting arms provided with hoisting steel wire ropes are hinged to the tower body; the lower part of the tower body is arranged on a foundation base; the top of the tower body, the end parts of the hosting arms and the leading-out beams are provided with pulley blocks connected with the hoisting steel wire ropes; an upper group of leading-out beams and a lower group of leaking-out beams are provided; the two groups of leading-out beams are provided with pulley blocks connected with the steel wire ropes respectively; an arm retracting steel wire rope is wound on the pulley blocks on the end parts of the hoisting arms and the pulley block on the top of the tower body, and is fixed on one group of leading-out beam pulley blocks through the tower body; the other group of leading-out beam pulley blocks is wound on the hoisting steel wire ropes; the foundation base is formed by assembling a plurality of same square foundation bottom blocks; the foundation bottom blocks are fixedly connected to a foundation chassis. In the scheme, the portable dual-flat-arm floor type derrick has the advantages of small size, light dead weight, detachability of the foundation base, and selection of bases of different sizes according to field environments.