The utility model discloses an integrated derrick of an under-pressure operation
machine. The integrated derrick comprises a prying frame, a
wellhead support, a main operation table, an auxiliary operation table, an upper base plate, a lower base plate and
hydraulic cylinder stand columns. The upper base plate is fixedly connected to the top of the prying frame, the lower base plate is fixedly connected to the middle of the prying frame, the two ends of the four sets of
hydraulic cylinder stand columns are fixedly connected with the upper base plate and the lower base plate respectively, the top end of the
wellhead support is fixedly connected with the lower base plate, and the side face of the bottom end of the
wellhead support is fixedly connected with the bottom of the prying frame. The prying frame, the well mouth support, the upper base plate, the lower base plate and the four sets of
hydraulic cylinder stand columns form a
rigid frame body of the integrated derrick. Most load or all load of the under-pressure operation
machine can be transmitted to the prying frame and the well mouth support to be borne, and the potential safety
hazard that an original well mouth device is crushed due to the fact that the original well mouth device bears large load is fundamentally eliminated; and the problem of deformation and leakage of the sealing ring of the connecting
flange caused by alternating load is fundamentally solved.