The operation unit with pressure for oily water well in oil field consists of upper cross beam, traveling slips, elevating hydraulic cylinder, energy accumulator, annular blowout preventer, transverse regulator, single ram blowout preventer, fixed slips, middle cross beam, elevating nipple, spherical blowout preventer, three ram blowout preventer, longitudinal regulator, lower cross beam, load display, coupler detector, oil tank water preventing loop unit and remote control system. The comprehensive operation unit with pressure has reasonable structure, high sealing performance, high safety and reliability, low cost and labor strength, and may be used in various kinds of complicated operation.