Nowadays, passive defense is very important in the field of military and urban management; Because by implementing preventive measures according to its instructions, the damages caused by the enemy's attack can be reduced to a great extent. One of the important measures in this field is the construction of shelters in the city in order to reduce human losses in times of crisis. The construction of shelters has considerations and rules, one of these considerations is the place of construction of shelters, which should be located in parts of the city where as many people as possible can reach there at the right time. In this research, the location of the urban shelter has been done with a passive defense approach and using multi-criteria decision making algorithms. First, the hierarchical analysis method was used to weight the criteria, then the criteria maps produced using fuzzy logic functions, fuzzification, and finally, the points were entered into the TOPSIS algorithm to be evaluated and prioritized. In this research, 39 information layers of Zahedan city were collected and categorized into 15 criteria. "Distance from sensitive and important centers" and "Distance from centers with support function" criteria with 23 and 13 percent of the highest weight, respectively; And "Distance from the railway line" and "Ground slope" have the lowest weight with 1 and 1 percent, respectively. After running the processing chain on the criteria, the output layer was produced and the final location map of the urban shelter was created. The results show that most of the areas in the east and north and to some extent the center of the city are unsuitable for building a shelter, because several negative factors such as the worn-out fabric of the city, dangerous and industrial centers, fault, surface water, underground water and part of the lines The transmission of high voltage electricity are all concentrated in the east and north of the city and have intensified each other, causing only the west and south of the city (and a few small areas in the east and southeast of the city) to be recognized as suitable for building a shelter.