The utility model relates to a hot metal pretreatment desulphurization lance. The technical scheme utilized includes that a lance body (1) is fixedly connected with a framework (3), a refractory material outer lining (2) is poured on the outer wall of the lance body (1), the framework (3) is embedded in the refractory material outer lining (2), a delivery pipe (4) is arranged in the lance body (1), the top end of a vaporizing chamber (5) is communicated with the tail end of the delivery pipe (4), the vaporizing chamber (5) is in a combined shape of a frustum and a cylinder or a cylinder shape, the tail end of the vaporizing chamber (5) is provided with a lance lower outlet, and lateral walls thereof are provided with 2-12 lance side outlets (6). The minimum included angle which is formed between the center line of each lance side outlet (6) and the isohypsic surface ranges from 0 degree to 60 degrees, and each lance side outlet (6) can be a circular hole, an elliptic hole, a flaring hole or a square hole. The hot metal pretreatment desulphurization lance has the advantages of reasonable structure, high desulfurizer utilization rate and high desulphurization efficiency. As air escapes from the hot metal uniformly with continuous bubbles, the lance is stable in injection process with small liquid level fluctuation and small spatter and has low small influence on production environments.