The utility model discloses a deep basal pit machinery adds tank instalation, suspend wire rope in midair, suspend the mount in midair and inlay the oil tank in suspending the mount in midair including at least two, suspend wire rope in midair and pass the steel pipe that suspends the mount in midair and inside and lay the back around the surface of oil tank, suspend wire rope in midair and suspend the mount in midair and constitute and suspend fixing device in midair, the up end of oil tank is provided with the oil tank switch cover, play oil pipe that the side of oil tank was provided with out oil valve and was connected with an oil valve, suspend the mount below in midair and install fork truck operation frame. Through oil tank, valve, the integrated oil tank that adds as an organic whole of fixing device, fork truck operation frame suspends in midair, has effectively solved the deep basal pit excavation machinery and has refueled the problem of difficulty, convenient to use in addition. Practiced thrift manpower, material resources, financial resources conveniently save time, improve work efficiency for the project progress.