The invention discloses a preparation method of broad bean puffed foods. The preparation method is characterized by comprising the following steps of: (1) weighing dry broad beans, pulverizing, adding an auxiliary material accounting for 20-30 percent of the weight of raw materials and uniformly mixing to obtain the raw materials; (2) respectively measuring the water contents of the broad beans and the auxiliary material; (3) adding water to the raw materials to ensure that the total water content is 20 percent and stirring to obtain a blank; (4) putting a mould into a discharge hole of single-screw extrusion puffing equipment and heating the discharge hole to 120 DEG C; (5) uniformly stirring the blank and feeding the blank from the feed inlet of the single-screw extrusion puffing equipment; (6) cutting and shaping broad bean products extruded from the port of the mould by using a rotating cutter; and (7) frying the broad bean products prepared in the step (6) by using palm oil, fishing out, uniformly spraying a prepared seasoning and cooling to room temperature to obtain a finished product. The broad bean puffed foods prepared by using the method are crisp and palatable and have simple and convenient process and low cost.