The invention discloses a hot dip coating tin technology for preventing the approach legs of SMT parts from bridging. The technology comprises the following steps: surface mounting parts are lower into a tin pan at an even rate and dipped in tin-lead solder liquid in a molten state for two to three seconds; the approach legs of the surface mounting parts are then lifted from the surface of the tin-lead solder liquid; hot wind spray nozzles which are communicated with a hot wind source are arranged on the left and the right sides above the surface of the tin-lead solder liquid; when the approach legs of the surface mounting parts are lifted from the surface of the tin-lead solder liquid, and before the tin-lead solders on a lead wire thereof become solid; the hot wind spray nozzles on the two sides allow high pressure hot wind produced by the hot wind source to form a left thin wind blade and a right thin wind blade; the left and the right thin wind blades are vertically arranged in a staggered manner and applied to two sides of the approach legs of the surface mounting parts; when clamps drive the surface mounting parts to ascend at an even rate and the approach legs pass through the wind blades, the wind blades uniformly brush the solders on the approach legs of the surface mounting parts once, so that the tin-lead solders on the surfaces of the approach legs of the surface mounting parts are thin and uniform, and the hot dip coating tin operation for surface mounting parts with approach legs arranged at small intervals.