The invention relates to an auxiliary hoisting frame for floating jacket mounting in shallow water. The auxiliary hoisting frame is arranged between two sub jackets, and the two sub jackets are connected integrally through the auxiliary hoisting frame. The auxiliary hoisting frame comprises an upper horizontal connection frame body, a lower horizontal connection frame body and two vertical support frame bodies. The upper horizontal connection frame body, the lower horizontal connection frame body and the two vertical support frame bodies are fixedly connected to form a cuboid frame. The top end of the cuboid frame is fixedly connected with the top ends of the two sub jackets respectively. An insertion tip used for being in insertion fit with a sleeve on the lower portion of the corresponding sub jacket is arranged at each of four corners of the bottom of the cuboid frame. The auxiliary hoisting frame has the advantages that relative displacement of the two independent sub jackets during mounting can be avoided, and a necessary guarantee is provided for floating mounting of an assembly; a fixed connection mode is adopted for overwater parts, and a movable connection is adopted for underwater parts, so that overwater operation is needed while underwater operation is not needed during demounting of the auxiliary hoisting frame, construction difficulty is reduced, and construction time is shortened.