This paper presents a fault tree analysis method based on fuzzy theory to evaluate the reliability of protection system for the household appliances. Since the actual environment where the faults of electrical appliances happen is uncertain, the concept of fuzzy set is firstly utilized to represent the rate of fault for the protection element. Then, the fault tree analysis method is applied to obtain the probability of protection system fault, and the possible strongest and weakest parts of protection systems can be justified by using significance analysis. Finally, the proposed solution procedure is tested with a large water-type household appliance and is verified via the Monte Carlo simulation. Compared results show that the proposed method is robust and practicable.