The invention discloses a positioning and guiding device. The positioning and guiding device comprises an actuating rod, a fixed piece and a positioning piece, wherein a part needing to be accurately positioned is fixed together with the positioning piece. The actuating rod is pivoted on the fixed piece. The positioning piece is pivoted at one end of the actuating rod, and the other end of the actuating rod is a force applying end. A muzzle of a heating gun is provided with a welding needle head, and the heating gun is provided with the positioning and guiding device. The fixed piece of the positioning and guiding device is fixed on the heating gun and the welding needle head is fixed on the positioning piece. The positioning and guiding device disclosed by the invention has the advantages that acting force is applied by the force applying end of the actuating rod to enable the actuating rod to pivot relative to the fixed piece and further drive the positioning piece fixed together with the actuating rod to move, so that accurate positioning of the part needing to be accurately positioned is realized. Due to the positioning and guiding device on the heating gun, the welding needle head can be accurately positioned, the left-right vibrating offset can be avoided, and the accurately-positioning effect is very obvious especially for the condition of a long welding needle, so that the reliability, the accuracy and the stability of welding can be improved and the welding quality can be ensured.