The invention relates to a welding seal adhesive tape and a preparation method thereof. The welding seal adhesive tape comprises a basic layer and a hot melt adhesive layer, the hot melt adhesive layer is sprayed on the basic layer, and the hot melt adhesive layer has a net-shaped structure which is formed by hot melt adhesive wires. The welding seal adhesive tape can solve surface treatment problems of sticky welding adhesive tapes, protect the adhesive effects between the welding adhesive tape and adhered surfaces, and solve the problem that operation of the adhesive surface is inconvenient, and meanwhile, the welding seal adhesive tape furthest guarantees the welding effects of adhered metals.