The invention provides a connecting assembly capable of being adjusted in three directions. The connecting assembly comprises a screw rod 1, a movable connecting part 2 with a long groove, a handle nut 3, a fixed connecting part a4, a circlip for shaft 5, a shaft fork 6, an adaptor 7, a spring gasket 8, a bolt 9, a baffle plate 10, a fixed connecting part b11 with a long groove, a gasket 12, a hinge pin 13, a split pin 14 and a movable handle 15, wherein one end of the screw rod 1 is connected with the movable handle 15 while the other end of the screw rod 1 is connected with the adaptor 7, and the middle of the screw rod 1 is connected with the movable connecting part 2 and the handle nut 3; the movable connecting part 2 and the fixed connecting part b11 are connected through the long grooves and the hinge pin 13 and can relatively move; one end of the shaft fork 6 is fixedly connected with the adaptor 7 through the baffle plate 10 while the other end of the shaft fork 6 is fixedly connected with the fixed connecting part a4 through the circlip for shaft 5. With the adoption of the connecting assembly, the connecting position of a product is accurate, safe and reliable; the dismounting method is simple; the rigid connection function is achieved; the requirement on adjustable connection in top and bottom, front and back, and left and right of two parts can be met.