The utility model relates to an installing and welding device for a guiding rail of a quakeproof component of a mechanical parking system. The installing and welding device comprises a hollow frame type main body bent body; a cushion plate is arranged in one side of the main body bent part; the cushion plate is fixedly connected with the main body bent part through a locating bolt; eccentric shafts are respectively arranged on the two sides of the cushion plate; the eccentric shafts are arranged on the main body bent part and are driven by a first handle on the outer side of the main body bent part to rotate in the axial direction; a pressing column is arranged on one side, opposite to the cushion plate, of the main body bent part; the pressing column is matched with the locating bolt; the pressing column is controlled by a second handle on the outer side of the main body bent part to be screwed in and out; fastening pins are respectively arranged on the other two sides of the main body bent part; the fastening pins are controlled by a third handle on the outer side of the main body bent part to be screwed in and out. The installing and welding device can fix the relative positions of the C-shaped parent body and the lateral guiding rail, so that the welding accuracy of the C-shaped parent body and the lateral guiding rail is guaranteed.