The invention discloses an assembling assembly for a trace fluid jetting device. The trace fluid jetting device comprises an execution system and a flow channel assembly, wherein the execution system comprises a base body, a movable element and a guide base, and the flow channel assembly comprises a fluid base, a fluid feeding connector, an adapter, a nozzle, a thread sleeve, a sealing base and a fluid cavity sealing part; the assembling assembly comprises a disassembling wrench and a disassembling sleeve; the disassembling wrench comprises a disassembling wrench body, one end of the disassembling wrench body is provided with a first bayonet which is suitable for being matched with a fast locking screw and the thread sleeve, and the other end of the disassembling wrench body is provided with a second bayonet which is suitable for being matched with the fluid feeding connector; and the disassembling sleeve comprises a cylindrical barrel, one end of the cylindrical barrel is provided with limiting protrusions, the limiting protrusions are matched with limiting holes in the sealing base so that the sealing base can be installed, the other end of the cylindrical barrel is provided with positioning convex tables, and the positioning convex tables are matched with installing notches in the guide base so that the guide base can be disassembled and assembled. According to the assembling assembly for the trace fluid jetting device, the assembling efficiency is improved, and maintenance and replacement are convenient to achieve.