The invention provides a method for dehumidifier welding blocking self detecting. When a dehumidifier is in a welding blocking self-detecting mode, welding blocking self detecting is carried out after the dehumidifier operates for preset time according to the set welding blocking self-detecting mode. If the fact that a welding blocking problem exists in a system is judged, the dehumidifier stops working, and welding blocking information is fed back. If the fact that the welding blocking problem does not exist in the system is judged, the dehumidifier is controlled to be out of the welding blocking self-detecting mode, and a normal operation mode is carried out. According to the method for dehumidifier welding blocking self detecting, during production, product welding blocking situations are detected automatically, the product quality of a production link can be controlled, faults such as product damage are reduced, production efficiency is improved, and the burden of after-sales service is relieved. Meanwhile, the self-detecting method and other existing control methods of the dehumidifier are independent, and accordingly under the situation that an after-sale product is used normally, the normal function cannot be affected.