The utility model discloses a formation testing gas operation raffinate does not fall to ground automatic recovery unit, at least, including the hydrops pond, the hydrops pond is by the jar body, a cover plate, dredge pump and block terminal are constituteed, wherein a jar body is open -top, bottom shutoff and big -end -up's rectangular pyramid type, the open -top terminal surface of the jar bodycan be dismantled and be connected with the apron, the shutoff bottom surface embedding ground of the jar body, jar body shutoff bottom surface fixedly connected with dredge pump and inscription havethe steel pipe of pipeline subassembly, wherein dredge pump and the inscription steel pipe that has a pipeline subassembly runs through the apron and extends to the apron top, it has offered two inlets with top to lie in ground on the wall of jar side, observation window has been seted up to two inlet intermediate positions, the jar position still can be dismantled on the lateral wall of ground with top and be connected with the block terminal. The utility model discloses cleaner production and environmental protection requirement are realized to the pollution of environment to the on -the -spot raffinate sewage fatlute of reduction formation testing gas, and on -the -spot overall process is airtight, avoids sump oil, oily sewage etc. To produce the fire explosion accident.